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A  PRACTICAL  TREATISE 

ON   THE 

MANUFACTURE  OF  VINEGAR  AND  ACETATES,  CIDER  AND 

FRUIT  WINES,  AND  THE  PRESERVATION  OF  FRUITS 

AND  VEGETABLES,  MEAT,  FISH  AND  EGGS. 


A  PRACTICAL  TREATISE 


ON 

THE  MANUFACTURE  OF  VINEGAR, 

WITH 

SPECIAL  CONSIDERATION  OF  WOOD  VINEGAR  AND    OTHER  BY- 
PRODUCTS OBTAINED  IN  THE  DESTRUCTIVE  DISTILLATION 
OF  WOOD  ;  THE  PREPARATION  OF  ACETATES. 

MANUFACTURE  OF  CIDER  AND  FRUIT-WINES ; 

PRESERVATION  OF  FRUITS  AND  VEGETABLES  BY 
CANNING  AND  EVAPORATION; 

PREPARATION   OF  FRUIT-BUTTERS,  JELLIES,  MARMALADES, 
PICKLES,  MUSTARDS,  ETC. 

PRESERVATION  OF  MEAT,  FISH  AND  EGGS. 


EDITED  FROM  VARIOUS  SOURCES 
BY 

WILLIAM  T.  BRANNT, 

EDITOR  OF   "THE   TECHNO-CHEMIGAL   RECEIPT  BOOK." 

THIRD  EDITION. 

THOROUGHLY   REVISED    AND  LARGELY   RE-WRITTEN. 
ILLUSTRATED    BY    ONE    HUNDRED   AND    ONE    ENGRAVINGS. 


PHILADELPHIA  : 
HENRY  CAREY  BAIRD  &  CO., 

INDUSTRIAL  PUBLISHERS,    BOOKSELLERS   AND  IMPORTERS, 

810  WALNUT   STREET. 

1914. 


COPYRIGHT  BY 

HENRY  CAREY  BAIRD  &  CO. 
1914. 


PRINTED  BY  THE 

WICKERSHAM    PRINTING   CO., 

111-117   E.   Chestnut  Street, 

LANCASTER,  PA.,  U.  S.  A. 


PREFACE  TO  THE  THIRD  EDITION. 


THE  second  edition  of  A  PRACTICAL  TREATISE  ON  THE 
MANUFACTURE  OF  VINEGAR  has  been  out  of  print  for  sometime, 
and  there  being  no  recent  work  to  take  its  place  notwithstand- 
ing the  constant  demand  for  a  book  on  the  various  important 
branches  of  industry  treated  of,  the  publication  of  a  new  edition 
was  deemed  advisable. 

Like  the  previous  editions  the  volume  is  divided  into  three 
parts. 

Part  I.  is  devoted  to  the  Manufacture  of  Vinegar,  and  in- 
cludes the  production  of  wood  vinegar  and  other  by-products 
obtained  in  the  destructive  distillation  of  wood,  as  well  as  the 
preparation  of  acetates. 

Part  II.  contains  the  Manufacture  of  Cider,  Fruit  Wines, 
etc.,  and  Part  III.  the  Preservation  by  various  methods  of 
Fruit  and  Vegetables,  and  of  Meat,  Fish  and  Eggs. 

In  this,  the  third  edition,  no  essential  changes  have  been 
made  in  the  arrangement  of  the  book,  bait  it  has  been  thor- 
oughly revised  and  largely  re-written,  old  and  obsolete  matter 
having  been  eliminated  and  new  material  introduced.  The 
best  authorities  have  been  diligently  consulted  and  freely 
drawn  on,  for  which  due  credit  has,  whenever  possible,  been 
given  in  the  text. 

It  is  hoped  that  this  new  edition  will  meet  with  the  same 
favorable  reception  as  the  previous  ones,  and  that  it  will  be  of 
practical  utility. 

A  copious  table  of  contents  as  well  as  a  very  full  index  will 
render  reference  to  any  subject  in  the  book  prompt  and  easy. 

PHILADELPHIA,  November  16,  1914. 

W.  T.  B. 

(v) 


322567 


CONTENTS. 


PART  I. 
VINEGAR. 

CHAPTER  I. 

INTRODUCTORY  AND  HISTORICAL. 

PAGE 

Nature  of  vinegar;  Early  knowledge  of  vinegar;  Use  of  vinegar  as  a  medicine 
by  Hippocrates;  Anecdote  of  Cleopatra;  Use  of  vinegar  by  Hannibal  for 
dissolving  rocks.  ...........  1 

The  process  of  increasing  the  strength  of  vinegar  by  distillation  described  by 
Gerber  in  the  eighth  century;  Other  early  historical  data  about  vinegar; 
Stael's  method  of  strengthening  vinegar;  Count  de  Laragnais  and  Marquis 
de  Courtenvaux'  experiments.  .  .......  2 

Loewitz's  method  of  strengthening  vinegar;  Glacial  acetic  acid;  Historical 
data  regarding  the  formation  of  an  acetic  body  in  the  destructive  distilla- 
tion of  wood;  Determination  of  the  exact  chemical  constitution  of  acetic 
acid  by  Berzelius,  and  that  of  alcohol  by  Saussure;  Historical  data  relating 
to  the  generation  of  acetic  acid;  Introduction  of  the  quick  process  of  manu- 
facturing vinegar,  in  1823,  by  Schiitzenbach;  Method  of  making  vinegar 
from  wine  made  known  by  Boerhave,  in  1732  ......  3 

Schiitzenbach' s  original  plan  of  working  still  in  use  in  some  localities;  Neces- 
sity of  progress  in  making  vinegar  by  the' quick  process;  Great  purity  of 
acetic  acid  as  at  present  prepared  from  wood;  "  Vinegar  essence"  and  its 
uses  .....  ..........  4 

Difference  between  the  pure  acetic  acid  produced  from  wood  and  vinegar  pre- 
pared from  various  materials;  Principal  defects  in  the  process  of  making 
vinegar  by  the  quick  process  in  general  use 5 

Probability  of  the  discovery  of  a  process  for  the  production  of  acetic  acid 
from  its  elements  .........  6 

CHAPTER  II. 

THEORY  OF  THE  FORMATION  OF  VINEGAR. 

Chemical  processes  by  which  acetic  acid  in  large  quantities  is  formed    .         .       7 
Liebig's  theory  of  the  formation  of  vinegar;  Present  view  of  the  formation  of 
vinegar;  Pasteur's  theory;  Difference  between  Pasteur's  and  Nageli's  views; 
Nomenclature  of  organisms  producing  fermentation;  The  vinegar  or  acetic 
ferment     .............       8 

(vii) 


Viii  CONTENTS. 

PAGE 

Occurrence  of  acetic  acid  in  nature;  Formation  of  acetic  acid  by  chemical 
processes;  Formation  of  acetic  acid  by  the  action  of  very  finely  divided 
platinum  upon  alcohol  ....  .  .  .  .  .  9 

Development  of  mother  of  vinegar;  Pasteups  investigations  regarding  the 
relation  of  mother  of  vinegar  to  the  formation  of  vinegar;  Botanical  na- 
ture of  the  organisms  causing  the  formation  of  vinegar  ...  .11 

Disease  causing  bacteria;  Hansen's  investigations  of  the  species  of  bacteria   .     12 

CHAPTER  III. 
THE  VINEGAR  FERMENT  AND  ITS  CONDITIONS  OF  LIFE. 

The  vinegar  ferment,  its  origin  and  its  distribution;  Fluid  especially  adapted 
for  nutriment;  Experiment  showing  the  conversion  of  wine  into  vinegar 
by  the  vinegar  ferment .13 

Difference  between  the  living  and  dead  ferment  as  seen  under  the  micro- 
scope; Requirements  of  the  ferment  for  its  propagation  .  .  .  .15 

Results  of  the  withdrawal  of  oxygen  from  the  ferment;  Experiment  showing 
the  great  rapidity  of  propagation  of  the  vinegar  ferment;  Conditions  for 
the  nutriment  of  the  ferment;  Factors  required  for  the  settlement  of  the 
vinegar  bacteria  upon  a  fluid  and  for  their  vigorous  propagation  .  .  1& 

Composition  of  the  nutrient  fluid;  A  large  content  of  alcohol  in  the  nutrient 
fluid  detrimental  to  the  vegetation  of  the  vinegar  ferment;  Experiment 
showing  that  the  ferment  cannot  live  in  dilute  alcohol  alone  .  .  .17 

Preparation  of  a  fluid  containing  all  the  substances  essential  to  the  nutriment 
of  the  ferment;  Sensitiveness  of  the  ferment  to  sudden  changes  in  the  com- 
position of  the  fluid  upon  which  it  lives;  The  process  of  nutriment  of  the 
vinegar  ferment.  .  .  .  .  .  .  .  .  .  .  .18 

Supply  of  air  required  for  the  ferment;  Limits  of  temperature  at  which  the 
propagation  of  the  ferment  and  its  vinegar-forming  activities  are  greatest; 
Effect  of  low  temperature  upon  the  ferment.  .  .  •  .  .  .19 

Reason  why  acetic  degeneration  is  not  known  in  cold  wine  cellars;  Reasons 
for  the  frequent  occurrence  of  disturbances  in  the  formation  of  vinegar  at 
a  high  temperature.  .  .........  20 

Mother  of  vinegar;  Origin  of  the  term;  Different  opinions  regarding  the  na- 
ture of  mother  of  vinegar;  Formation  of  mother  of  vinegar.  .  .  .  21 

Summary  of  the  theoretical  conditions  of  frhe  formation  of  vinegar.       .         .     22 

CHAPTER  IV. 

PRODUCTS  OF  ACETIC  FERMENTATION. 

The  regular  propagation  of  the  ferment  the  main  point  of  the  entire  manu- 
facture; Loss  of  alcohol  in  the  production.  ......  23 

Substances,  besides  alcohol  and  carbonic  acid,  formed  in  vinous  fermentation. 
Characteristic  properties  imparted  to  alcohol  by  fusel  oils;  Aromatic  sub- 
stances which  reach  the  vinegar  through  the  conversion  of  fusel  oils; 
Acetic  aldehyde  or  acetaldehyde,  commonly  called  aldehyde.  .  .24 

Preparation  of  pure  aldehyde;  Acetal  and  its  preparation.       .         .  •     25 


CONTENTS.  IX 

PAGE 

Composition  and  nature  of  pure  acetal 26 

Acetic  acid  and  its  properties.         .........     27 

Peculiar  behavior  of  mixtures  of  acetic  acid  and  water  in  regard  to  their  spe- 
cific gravity;  Vinegar  essence  and  its  use  for  the  preparation  of  table  vin- 
egar; Composition  of  acetic  acid.        ........ 

Theoretical  yield  of  acetic  acid.        .         .         .         .         .         .         .  29 

Manner  of  calculating  the  theoretical  yield  of  acetic  acid  from  alcohol.         .     30 
Quantity  of  oxygen    required   to  form   acetic  acid  and  water  from  alcohol; 
Quantity  of  alcohol  which  can  daily  be  converted  into  vinegar  by  a  gene- 
rator  ( 31 

Calculation  of  the  quantity  of  heat  liberated  by  the  conversion  of  alcohol  in- 
to acetic  acid;  What  the  manufacturer  can  learn  from  theoretical  expla- 
nations   . 32 

The  acme  of  temperature  and  what  is  meant  by  it;  Loss  of  alcohol  and  acetic 
acid  by  evaporation  and  its  reduction.        .......     33- 

Conditions  on  which  the  most  advantageous  working  depends;  Yields  of  acetic 
acid  obtained  in  practice    .         .         .         .         .         .         .         .         .         .     34 

Comparison  of  a  vinegar  generator  to  a  furnace      .         .         .         .         .         .35 

CHAPTER  V. 

METHODS  OF  MANUFACTURE  OF  VINEGAR. 
Designation  of  the  various  methods  employed;  Substances  which  may  be  used 

for  the  preparation  of  vinegar    .........     36 

Alcohol  the  ultimate  material  for  the  manufacture  of  vinegar;  The  old  or 

slow  process  and  modifications  of  it 37 

Difference  in  the  properties  of  vinegar  derived  from  various  sources      .         .     38 

CHAPTER  VI. 

QUICK  PROCESS  OF  MANUFACTURE  OF  VINEGAR. 
Invention  of  Schiitzenbach  and  analogous  processes;  On  what  the  principle 

involved  depends;  Comparison  of  the  generator  or  graduator  to  a  furnace  .     39 
Generators;  Best  form  of  the  generator.         .......     40 

Kinds  of  wood  suitable  for  the.construction  of  generators       .         .         .         .41 

Variations  in  the  dimensions  of  the  generators       ......     42 

Dimensions  of  the  most  suitable  generator;  Cover  of  the  generator         .         .     43 
Disadvantage  of  a  number  of  obliquely  bored  holes  below  the  false  bottom; 

Scheme  of  incorrect  conduction  of  air  in  generators    .....     44 
Contrivances  for  the  discharge  of  vinegar  collected  in  the  lower  portion  of 

the  generator     ............     45 

Arrangement  of  the  perforated  false  head  of  the  generator     .         .         .         .     46 

Arrangement  for  regulating  the  inflow  of  air  from  below        .         .         .         .47 

Modification  of  the  false  head         .          .         .         .          .         •  .          .48 

The  tilting  trough 49 

The  sparger  .............     50 

Principal  requisite  for  the  correct  working  of  the  sparger      .         .         .         .51 


X  CONTENTS. 

PAGE 

A  thermometer  an  indispensable  adjunct  to  a  generator;  Filling  the  gener- 
ators, and  materials  used  for  this  purpose.  ......  52 

•General  use  of  beech  shavings,  their  advantages  and  preparation;  Volume 
represented  by  a  shaving  in  a  rolled  state;  Space  required  for  such  shaving.  53 

Freeing  the  shavings  from  extractive  substances  by  water  and  by  steaming; 
Drying  the  steamed  shavings 54 

Swelling  the  shavings  and  placing  them  in  the  generator;  Advantage  of  hav- 
ing all  the  generators  of  the  same  size.  .......  55 

CHAPTER  VII. 
ARRANGEMENT  OF  A  VINEGAR  FACTORY. 

Principal  requisites  to  be  observed  in  a  suitable  arrangement;  Provisions  for 
the  maintenance  of  a  uniform  temperature .58 

Materials  for  the  floor;  Heating  of  the  workroom,  and  apparatus  for  this  pur- 
pose ..............  57 

Advantage  of  the  use  of  maximum  and  minimum  thermometers    .         .         .59 

Location  of  the  reservoirs  in  factories  arranged  according  to  the  automatic 
system 60 

CHAPTER  VIII. 

ARTIFICIAL  VENTILATION  OF  THE  VINEGAR  GENERATORS. 

English  process  of  sucking  a  current  of  air  from  above  to  below  through 

every  generator;  Incorrectness  of  this  method 61 

Principal  reason  advanced  for  the  use  of  a  current  of  air  from  above  to 

below -  62 

Schulze's  ventilating  apparatus  and  generator        ......  63 

Generators  with  constant  ventilation  and  condensation;  An  apparatus  well 

adapted  for  the  purpose      ..........  65 

Proposed  method  of  regaining  the  vapors;  Objection  to  this  method      .         .  68 

4Singer*  s  general  >r 69 

Michaelis'  revolving  generator       .........  72 

CHAPTER  IX. 
AUTOMATIC  VINEGAR  APPARATUS. 

Principal  work  which  has  to  be  performed  in  a  vinegar  factory;  Disadvan- 
tages of  pouring  at  stated  intervals  the  alcoholic  fluid  into  the  generators.  73 

Debilitation  of  the  vinegar  ferment  in  consequence  of  repeated  reduction  of 
the  temperature  in  the  generators;  Explanation  of  many  apparently  inex- 
plicable disturbances  .........  74 

Advantages  to  be  derived  from  the  use  of  simple  automatic  contrivances; 
Continuously-acting  apparatus;  The  terrace  system  .  .  .  .  .75 

Arrangement  of  a  factory  according  to  the  terrace  system;  Drawback  of  this 
system  ...........  77 


CONTENTS.  XI 

PAGE 

Mode  of  working  according  to  the  terrace  system 78 

Lenze's  chamber  generator,  and  the  principles  upon  which  its  construction  is 

based 80 

Mode  of  operating  Lenze's  chamber  generator;  Plate  generator,  patented  by 

Dr.  Bersch 82 

Periodically  working  apparatus;  The  three-group  system;  Mechanical  appli- 
ances for  admitting  at  certain  intervals  a  fixed  quantity  of  alcoholic  fluid 
into  the  generators;  Modification  of  the  tilting  trough  .  .  .  .86 

The  siphon  barrel 88 

The  bell-siphon  ;  Example  for  calculating  the  space  required  beneath  the 

false  bottom  for  the  reception  of  the  vinegar 89 

Arrangement  of  a  vinegar  factory  working  according  to  the  automatic  prin- 
ciple; Arrangement  of  the  generators  in  groups.         .         .         .         .         .90 

Description  of  a  periodically-working  establishment  with  24  generators.         .     91 
Manner  of  working  in  such  an  establishment.         ......     93 

Apparatus  for  heating  the  alcoholic  liquid     .......     95 

i 
CHAPTER  X. 

OPERATIONS  IN  A  VINEGAR  FACTORY. 

Acetification  of  the  generators;  Quantities  of  vinegar  required  for  complete 
acetitication        .         .         .         .         .         .         .         .         .         .         .         .96 

Example  illustrating  the  gradual  commencement  of  regular  production;  Ac- 
celerated acetification         ..........     97 

How  the  removal  of  water  from  the  shavings  and  its  substitution  by  vinegar 
are  effected         ............     98 

Use  of  artificially  dried  shavings;  Induction  of  the  operation  with  an  artifi- 
cial culture  of  vinegar  ferment.          .......          .99 

Pure  culture  of  vinegar  ferment  and  best  fluid  for  the  purpose.      .         .         .  100 

Preparation  of  nourishing  fluid;  Manner  of  cultivating  vinegar  ferment.      .  101 

Abortive  culture  of  vinegar  ferment 102 

Disturbances  by  suddenly  changing  the  nutrient  fluid  of  the  ferment,  and 
their  prevention.  ...........  103 

CHAPTER  XI. 
PREPARATION  OF  THE  ALCOHOLIC  LIQUID. 

Definition  of  the  term  'alcoholic  liquid;"  Reason  why  a  content  of  vinegar 
in  the  alcoholic  liquid  exerts  a  favorable  effect  upon  the  formation  of  vin- 
egar.   104 

Proof  that  the  alcoholic  liquid  does  not  require  any  considerable  quantity  of 
acetic  acid  for  its  conversion  into  vinegar.  .  .....  105 

Reason  why  it  is  preferable  to  gradually  increase  the  content  of  alcohol  in 
the  alcoholic  liquid;  Experiment  showing  the  destruction  of  acetic  acid  by 
the  vinegar  ferment  in  the  absence  of  alcohol 106 


Xil  CONTENTS. 

PACK 

Limit  of  acetic  acid  vinegar  should  have  ;  Conditions  on  which  the  advanta- 
geous manufacture  of  high-graded  or  weak  vinegar  depends ;  Quantity  of 
beer  to  be  added  to  the  alcoholic  liquid .107 

Quantity  of  finished  vinegar  to  be  added  to  the  alcoholic  liquid;  Table  of 
the  theoretical  yield  of  acetic  acid  from  alcohol  .  .  .  .308 

lleason  why  practically  less  vinegar  with  a  smaller  percentage  of  acetic  an- 
hydride is  obtained  ;  Table  showing  the  content  of  alcohol  required  in  an 
alcoholic  liquid  for  the  production  of  vinegar  with  a  certain  content  of 
acetic  acid  ;  Calculation  for  finding  the  number  of  gallons  of  water  which 
have  to  be  added  to  alcohol  of  known  strength  to  obtain  an  alcoholic  liquid 
with  the  desired- percentage  of  alcohol 109 

Examples  of  the  composition  of  alcoholic  liquid    .         .         .         .         .         .110 

Use  of  low  wine  for  the  preparation  of  alcoholic  liquid  .         .         .         .         .111 

Determination  of  the  content  of  alcohol  in  spirits  of  wine  ;  Compilation  show- 
ing the  manner  of  preparing  alcoholic  liquid  according  to  rational  princi- 
ples  , 112 

Determination  of  acetic  acid  in  vinegar;  Constitution  of  the  fundamental 
materials  used  in  the  preparation  of  alcoholic  liquid  .  ....  113 

Water  suitable  and  unsuitable  for  the  preparation  of  vinegar;  Behavior  of 
mixtures  of  water  and  alcohol  .  .  .  .  .  .  .  .  .114 

River  water  and  the  possible  introduction  of  vinegar  eels  by  it;  Importance 
of  the  constitution  of  the  spirits  of  wine  used 115 

Advisability  of  using  a  mixture  of  rectified  and  crude  potato  alcohol     .         .   116 

CHAPTER  XII. 
EXECUTION  or  THE  WOBK  IN  A  VINEGAR  FACTORY. 

Simplicity  of  the  work;  Reduction  of  alcohol  with  water         .         .         .         .117 

Quantity  of  fluid  to  be  worked  in  a  generator  in  the  course  of  a  day;  Gradual 
strengthening  of  the  alcoholic  liquid  with  alcohol  .....  118 

Temperature  to  be  maintained  in  the  interior  of  the  generators;  Determina- 
tion of  acetic  acid  and  of  alcohol  in  the  fluid  running  off  from  the  gener- 
ators  119 

Plan  of  operation  as  resolved  from  the  results  of  tests    .....   120 

The  actual  prodoction  according  to  the  old  method;  Production  of  so-called 
triple  vinegar  ............  121 

Group  system;  Principle  of  the  operation;  Operation  with  three  groups  of 
generators.  .  .  .  .  .  .  .  .  .  .  .  .122 

Taking  samples  for  determining  the  content  of  acetic  acid  and  alcohol;  Cross- 
ing the  generators  .  .  .  .  .  .  .  .  .  .  .124 

Group  system  with  automatic  contrivances;  Preparation  of  the  alcoholic 
liquid  for  12  per  cent,  vinegar  .  .  .  .  .  .  .  .  .125 

Regulation   of  the  automatic  contrivances;    Operation   with    the  automatic 

system        .  126 

Recognition  of  a  disturbance  in  any  one  of  the  generators,  and  its  preven- 
tion .  .127 


CONTENTS.  Xlll 

PAGE 

CHAPTER  XIII. 

DISTURBING  INFLUENCES  IN  THE  MANUFACTURE  OF  VINEGAR. 
How  serious  disturbances  can  be  avoided;  Irregularities  due  to  the  nourish- 
ing substances  of  the  ferment,  and  how  to  remedy  them     ....   128 

Sweet  beer  wort  or  malt  extract  for  strengthening  weak-working  generators; 
Favorable  effect  of  phosphates;  Disturbances  ascribable  to  the  quantity  of 
newly-formed  acetic  acid    .         .         .         .         .         .         .         .         .         .129 

Controlling  the  working  of  the  generators  by  frequent  determinations  of  the 
acetic  acid;  Phenomena  indicative  of  the  generator  not  being  able  to  mas- 
ter the  alcoholic  liquid  introduced;  Restoration  of  the  generator  to  a  proper 
state  of  working         ...........   130 

Cause  of  the  heating  of  generators;  Sliming  of  the  shavings  in  generators      .  131 
Causes  of  sliming;  Alteration  which  takes  place  in  the  shavings    .         .         .  132 
Constitution   of  the  slimy  coat;   How  sliming  can  be  remedied  at  the  com- 
mencement of  the  evil        .         .         .         .         .         .         .         .         .         .  133 

Disturbances  due  to  vinegar  eels    .........   135 

Remedies  for  the  suppression  of  vinegar  eels.         ......  137 

Sulphuring  the  generator  and  apparatus  for  that  purpose       ....  138 

Disturbances  due  to  vinegar  lice  (vinegar  mites)     .         .         .         ...         .  140 

Vinegar  flies 142 

CHAPTER  XIV. 
SLOW  PROCESS  OF  MAKING  VINEGAR. 

Utensils  required,  Induction  of  the  formation  of  vinegar;  The  wash  and  its 
preparation  ............  143 

Indications  of  the  commencement  of  acetification;  Excitation  of  "  lazy  " 
barrels 144 

Time  required  for  acetification;  Barreling  and  storing  the  vinegar;  Modifi- 
cations of  the  slow  process.  .........  145 

Household  manufacture  of  vinegar         .          .         .         .          .         .         .         .147 

Preparation  of  vinegar  with  the  assistance  of  platinum  black         .         .         ..  148 

CHAPTER  XV. 
FURTHER  TREATMENT  OF  THE  FRESHLY-PREPARED  VINEGAR. 

Odor  of  freshly-prepared  vinegar,  and  on  what  it  depends;  Filling  the 
barrels 149 

Means  of  improving  the  odor  of  vinegar          ..'.....   150 

Drawing  oft' the  vinegar  from  the  sediment  in  the  barrel;  Constituents  of  the 
vinegar  brought  into  storage  barrels  ........  151 

Storing  of  vinegar;  Processes  which  take  place  during  storing.         .          .      .   152 
Filtering  vinegar  before  bringing  it  into  the  storage  barrels;  Heating  the 
vinegar,  and  apparatus  used.       .........   153 

Filtration  of  vinegar  and  filters  for  this  purpose 155 


CONTENTS. 

PAGE 

Sulphuring  of  vinegar.         .  158 

Fining  vinegar;  Coloring  vinegar.         ........   159 

CHAPTER  XVI. 

PREPARATION  OF  VlNEGAR  FROM  VARIOUS   MATERIALS. 

Formation  of  diastase;  How  vinegar  may  be  made  from  starch.       .         .       .   160 

Beer-wort  not  a  suitable  material  for  vinegar.         .         .         .         .         .         .161 

Fermented  whiskey  mashes  for  the  manufacture  of  vinegar;  Manufacture  of 

malt  or  grain  vinegar. 162 

Most  suitable  variety  of  malt  for  making  vinegar 163 

Theoretical  part  in  mashing;  After-effect  of  the  diastase 164 

"Doughingin" 165 

On  what  the  strength  of  the  vinegar  to  be  made  depends;  Setting  the  mash 
with  yeast;  Preparation  of  compressed  yeast;  Treatment  of  the  completely 
fermented  "ripe"  mash;  Heating  the  mash.       ......  166 

Conversion  of  the  fermented  malt-wort  into  vinegar.      .         .         .         .         .167 

Filtration  of  malt  vinegar  in  rffininy  or  rape  vessels;  Manufacture  of  malt 

vinegar  by  "fielding"  ;  Utilization  of  sour  ale  and  beer  for  vinegar.      .      .   168 
Vinegar  from  sugar  beets,  and  from  sugar,  fruits  and  berries.         .         .         .   169 

Making  vinegar  on  a  small  scale  for  domestic  use.         .         .         .         .          .170 

Table  showing   the  average  content  of  sugar  and  free  acid  in  the  most  com- 
mon varieties  of  fruits;  Treatment  of  currant  juice  for  making  vinegar.     .   171 
Preparation  of  vinegar  from  other  berries.       .......  172 

Peaches  as  vinegar  stock;  Cider  vinegar.         .......  173 

Use  of  a  generator  for  the  conversion  of  cider  into  vinegar;  Directions  for 
home-made  cider  vinegar,  by  Mr.  Walter  G.  Sackett 174 

CHAPTER  XVII. 

VINEGAR  SPECIALTIES. 

Groups  of  specialties;  Perfumed  vinegar;  Aromatized  vinegar       .         .         .   178 

Manner  of  dissolving  volatile  oils  in  vinegar         ......   179 

Preparation  of  aromatized  vinegar;  Toilet  vinegars;  Mohr's  volatile  spirits  of 
vinegar;  Aromatic  vinegar  .........  180 

Henry's  vinegar;  Vinaigre  des  quatre  voleurs;  Hygienic  or  preventive  vine- 
gar; Cosmetic  vinegar;  Table  vinegars;  Anise  vinegar  .  .  .  .181 

Anchovy  vinegar;  Tarragon  vinegar;  Compound  tarragon  vinegar;  Effervesc- 
ing vinegar 182 

Herb  vinegar;  Pineapple  vinegar;  Celery  vinegar;  Clove  vinegar;  Lovage 
vinegar;  Raspberry  vinegar 183 

Preparation  of  acetic  ether. 184 

CHAPTER  XVIII. 
MANUFACTURE  OF  WINE  VINEGAR. 

Materials  for  wine-vinegar;  Theoretical  and  actual  yield       ....   186 
Reasons  why  wine-vinegar  is  superior  to  the  ordinary  products     . ,        ;         .   187 


CONTENTS.  XV 

PAGE 

Table  showing  the  composition  of  wine  and  of  the  vinegar  formed  from  it; 

"Sick"  wines 188 

Lactic  acid  and  acetic  degenerations  of  wine         ......   189 

Young  wine  attacked  by  acid  degeneration  for  making  vinegar;  Preparation 
of  after-wine,  according  to  Petiot      .         .         .         .         .         .         .         .190 

Use  of  this  wine  for  making  vinegar     ........   192 

Older  method  of  making  wine  vinegar;  Orleans  or  old  French  process  of 

making  wine-vinegar .193 

Pasteur's  or  modern  French  method  of  preparing  wine-vinegar     .         .         .   196 
Pasteurization  and  apparatus  used;  Undesirable  phenomena  which  may  ap- 
pear in  the  conversion  of  wine  into  vinegar       ......  198 

Claudon's  method  of  making  wine-vinegar  described  by  Frederic  T.  Bioletti.  200 
Bersch's  method  of  making  wine-vinegar;  Culture  of  pure  vinegar  ferment  .   201 
Variety  of  wine  most  suitable  for  making  vinegar         .         .         .         .         .  203 

Apparatus  for  making  wine  vinegar     ........  204 

Operation  in  a  wine-vinegar  factory      ........   205 

Disturbances  in  the  production  of  wine-vinegar;  Filtering  wine-vinegar         .  208 
Storing  and  bottling  wine-vinegar;   Pasteurizing  bottled  vinegar  and  appa- 
ratus for  that  purpose       ..'....         .....  209 

Wine-vinegar  by  the  quick  process       .         .         .         .         .         .         .         .210 

Wine-vinegar  from  marc     .         .         .         .         .         .         .         .         .         .211 

CHAPTER  XIX. 

CHEMICAL  EXAMINATION  OF  THE  RAW  MATERIALS,  AND  CONTROL  OF  THE 
OPERATIONS  IN  A  VINEGAR  FACTORY. 

Determination  of  sugar         ..........  213 

Determination  of  alcohol;  The  alcoholometer 214 

Determination  of  the  alcohol  by  the  distilling  test,  and  apparatus  used.         .  215 

Determination  of  the  alcohol  by  the  ebullioscope 217 

Vidal-Malligaud's  ebullioscope    .........  218 

Determination  of  the  content  of  acetic  anhydride  in  vinegar,  or  acetometry: 

Titration  or  volumetric  analysis,  and  apparatus  for  that  purpose        .         .  220 
Calculation  of  the  quantity  of  acetic  acid  in  the  vinegar  examined;  Determi- 
nation of  the  strength  of  vinegar  by  the  vinegar  tester,  described  by  Fred- 
.eric  T.  Bioletti         .  224 

CHAPTER  XX. 

EXAMINATION  OF  VINEGAR  AS  TO  THE  PRESENCE  OF  FOREIGN  ACIDS  AND  OF 
METALS,  AS  WELL  AS  TO  ITS  DERIVATION. 

Detection  of  acids;  Sulphuric  acid 227 

Hydrochloric  acid;  Nitric  acid;  Lactic  acid;  Sulphurous  acid       .         .         .  228 

Detection  of  metals;  Iron;  Copper;  Tin 229 

Determination  of  the  derivation  of  a  vinegar         ......  230- 


XVI  .  CONTENTS. 

PAGE 

CHAPTER  XXI. 
WOOD- VINEGAR  AND  OTHER  BY-PRODUCTS  OBTAINED  IN  THE  DESTRUCTIVE 

DISTILLATION  OF  WOOD. 

Constitution  of  wood;  Specific  gravity  of  different  woods  ....  233 
Average  composition  of  air-dry  wood;  Decomposition  of  wood  .  .  .  234 
Effect  of  heating  on  wood;  Effect  of  acids  on  wood  .....  235 

Effect  of  dilute  aqueous  solutions  of  alkalies  on  cellulose 236 

Products  of  destructive  distillation;  Gaseous  products  of  distillation       .        .   237 
Table  showing   the  order  in  which    the  gaseous  combinations  are  formed  at 
different  temperatures;  Composition  of  wood  gases.         ....   238 

Origin  of  many  bodies  which  appear  among  the  products  of  the  decomposi- 
tion of  wood.          .          .         .          .          .......   239 

•Quantity  of  gas  yielded  by  wood  by  destructive  distillation.          .         .          .  241 

Liquid  products  of  distillation;  Wood  vinegar;  Fatty  acids  in  wood  vinegar  242 
Production  of  methyl  alcohol  from  marsh  gas;  Formation  of  acetone.  .  243 

Variation  in  the  quantities  of  the  bodies  of  which  wood-vinegar  is  composed; 

Tar .  i>44 

•Composition  of  the  larger  quantity  of  the  tar  products;  Combinations  which 
are  definitely  known.         .         .         .         .         .         .         .         ...   245 

"Yield  of  tar  obtained  in  the  destructive  distillation  of  wood;  Table  of  bodies 
of  technical  importance  appearing  in   the  destructive  distillation  of  wood.   246 

'Character  of  wood  tar  ;  Retort  tar ;  Boiled  tar -      .       .  247 

Properties  of  the  combinations  formed  in  wood  tar;  Acetic  acid;  Acetone.     .  248 
Methyl  acetate;  Aldehyde  or  acetaldehyde;  Methyl  alcohol  or  wood  spirit  249 
Tar  products — hydrocarbons  of  the  series  CnH2n-6       •  250 

Naphthalene  and  paraffin.          .          .          .          .         .         .         .         .         .  251 

Tar  products  containing  oxygen  (creosote);  Properties  of  wood-tar  creosote  252 
Illuminating  gases  from  wood;  Complete  series  of  compounds  occurring  in  wood 
tar  mentioned  by  various  chemists.       ........   253 

CHAPTER  XXII. 

PREPARATION  OF  CHARCOAL,  WOOD  VINEGAR,  AND  TAR  IN  CLOSED  VESSELS. 
Selection  of  the  apparatus  for  the  installation  of  a  plant  for  the  utilization  of 

wood  in  a  thermo-chemical  way.         ........  254 

Processes  by  which  acetic  acid  on  a  large  scale  can   be  prepared.         .         .  255 

Kilns  or  ovens  and  retorts;  Charring  of  wood  in  heaps  or  pits.      .          .         .  256 

Schwartz's  oven         .          .                   .                   ......  257 

Reichenbach's  oven     .         .         .         .         .         .         .         .         .         .         .  259 

Swedish  oven 260 

Carbo-oven ;  Retorts 262 

Horizontal  retorts;  Wrought-iron  retort  of  suitable  construction  .         .         .  263 

Manner  of  bricking  in  six  retorts 2(54 

Utilization  of  the  gases  escaping  from  the  condenser  for  heating  .         .         .  266 

-Oven-retort  largely  used  in  this  country;  Coolers;  Vertical  retorts         .          .  267 

-Arrangement  of  the  retort-ovens  and  the  lifting  apparatus    ....  268 


CONTENTS.  XVU 

PAGE 

Distilling  apparatus  for  wood  waste;  Halliday's  apparatus     ....  271 
Apparatus  suitable  for  the  distillation  of  sawdust  and  waste  of  wood  in  gen- 
eral  273 

On  what  the  selection  of  apparatus  for  the  destructive  distillation  of  wood 

depends 274 

Coolers;  Counter-current  pipe  cooler     ........   275 

Most  suitable  way  of  connecting  two  pipes    .......   276 

Prevention  of  obstruction  in  the  pipes.         .......   277 

Box  cooler;  Collection  of  gas        .........  278 

Reservoirs  for  the  product  of  distillation 279 

Collecting  boxes 281 

Utilization  of  the  gases         .         .         .  .         .         .         .         .         .   282 

CHAPTER  XXIII. 

EXECUTION  OF  THE  DESTKUCTIVE  DISTILLATION  OF  WOOD. 
Operation  with  a  larger  number  of  retorts;  On  what  the  time  during  which 
distillation  has  to  be  continued  depends    .......  284 

Mode  of  placing  a  thermometer  in  one  of  the  retorts    .....  2K5 

Use  of  antimony  in  determining  the  commencement  of  the  end  of  distillation.  286 
Size  of  vats  for  the  reception  of  the  distillate;  Collecting  boxes  sunk  in  the 

ground 287 

Yield  of  products;  Manner  in  which  accurate  data  regarding  the  quantities 
of  wood-vinegar  and  tar  from  a  variety  of  wood  may  be  obtained;  Stolze's 
experiments     ............   288 

Results  obtained  by  Assmus  in  manufacturing  on  a  large  scale;  Yields  ob- 
tained with  retorts,  according  to  Klar 289 

CHAPTER  XX1Y. 

TREATMENT  OF  THE  WOOD- VINEGAR. 
Uses  of  crude  wood-vinegar;  Separation  of  acetic  acid.         ....   290 

Separation  of  the  wood-vinegar  fr  m  the  tar;  Methods  by  which  concentrated 
acetic  acid  can  be  obtained  from  crude  wood-vinegar.         .         .         .         .  291 

Distilled  wood-vinegar         ..........  292 

F.  H.  Meyer's  system  of  distilling  the  crude  wood-vinegar  in  multiple  evap- 
orators in  vacuum;  Properties  of  freshly-distilled  wood-vinegar.         .         .   293 
Various  methods  proposed  for  the  purification  of  wood-vinegar    .         .         .  294 
Production   of  pure  acetic  i  cid  from  wood-vinegar;  Preparation  of  calcium 
acetate     .............   296 

Evaporating  pans         ...........  297 

Klar's  continuously. working  apparatus  for  evaporating  and  drying  the  cal- 
cium acetate     ............  298 

Preparation  of  sodium  acetate      .........  299 

Filter  for  obtaining  pure  sodium  acetate       .......  301 

Mode  of  obtaining  sodium  acetate  for  the  preparation  of  perfectly  pure  acetic 
acid  .  302 


XV111  CONTENTS. 

PAGK 

Preparation  of  sodium  acetate  from  calcium  acetate 304 

Preparation  of  acetic  acid  from  the  acetates;  Processes  used;  Hydrochloric 
acid  process     ............  305 

Sulphuric  acid  process.         ..........   307 

Plant  arranged  for  the  sulphuric  acid  process 308 

Preparation  of  glacial  acetic  acid.         ........  309 

Vacuum  process  for  obtaining  highly  concentrated  acetic  acid       .         .         .310 
Preparation  of  glacial  acetic  acid  of  the  highest  concentration       .         .         .311 

CHAPTER  XXV. 

ACETATES  AND  THEIR  PREPARATION. 
Properties  of  acetates  .         ...........  313 

Potassium  acetate         ...........  314 

Potassium  acid  acetate  or  potassium  diacetate;  Sodium  acetate;  Ammonium 
acetate,  neutral  acetate  of  ammonia  .         .         .         .         .         .         .316 

Calcium  acetate;  Barium  acetate.         .         .         .         .         .         .         .         .  317 

Magnesium  acetate      ...........   319 

Aluminium  acetate;  Normal  or  f  aluminium  acetate;  Basic  aluminium  §  ace- 
tate; Basic  aluminium  g  acetate        ........   320 

Maganese  acetate 323 

Iron  acetate;  Ferrous  acetate,  black  mordant 324 

Neutral  ferric  acetate,  sesquiacetate  of  iron.         ......  326 

Chromium  acetate;  Chromous  acetate;  Nickel  acetate;  Cobalt  acetate    .         .  328 
Zinc  acetate;  Copper  acetates;  Cuprous  acetate;  Neutral  cupric  acetate,  crys- 
tallized verdigris 329 

Basic  cupric  acetates;  Sesquibasic  cupric  acetate   ......  332 

Tribasic  cupric  acetate;  French  and  English  verdigris.         ....  333 

Lead  acetates;  Neutral  acetate  of  lead  (sugar  of  lead);  Volkel's  method         .  335 
Stein's  method,  and  distilling  apparatus  used       ......   337 

Crystallizing  pans         ...........   338 

Preparation  of  sugar  of  lead  from  metallic  lead,  according  to  Berard     .         .  340 
Brown  acetate  of  lead  .         ..........   341 

Properties  of  acetate  of  lead 342 

Basic  lead  acetates;  Manufacture  of  white  lead  according  to  the  French 
method;  Lead  vinegar  or  extract  of  lead..         ......  344 

Lead  sesquibasic  acetate,  triplumbic  tetracetate    ......   345 

Sexbasic  acetate  of  lead;  Uranium  acetate;  Tin  acetate;  Bismuth  acetate;  Mer- 
curous  acetate.         ...........  346 

Mercuric  acetate;  Silver  acetate 347 

CHAPTER  XXVI. 

PREPARATION  OF  PURE  WOOD  SPIRIT  OR  METHYL  ALCOHOL.  AND  OF 

.     ACETONE,  AND  WORKING  THE  WOOD  TAR. 

Preparation  of  wood  spirit;  Constitution  of  the  crude  wood  spirit  of  com- 
merce; Wood  spirit  for  denaturing  purposes      ......  348 


CONTENTS.  XIX 

PAGE 

Constitution  of  pure  wood  spirit;  Rectification  of  crude  wood  spirit  solutions, 

and  still  for  the  purpose  ..........  3-19 

Preparation  of  wood  spirit  suitable  for  denaturing  purposes  ....  351 

Preparation  of  acetone;  Properties  of  acetone;  Decomposition  of  the  calcium 

acetate,  and  apparatus  for  this  purpose 352 

Rectification  of  the  crude  distillate;  Arrangement  of  a  plant  for  the  produc- 
tion of  acetone.         ...........  353 

Manufacture  of  pure  acetone  according  to  F.  H.  Meyer's  system;  Working 

the  wood  tar;  Preparation  of  creosote  and  tar  oils;  Distillation  of  wood  tar  355 

Yield  from  tar  of  hard  woods  by  distillat  on          ......  350 

Rectification  of  the  oils;  Manner  of  obtaining  creosote  from  the  distillate      .  357 

Working  the  heavy  oils;  Results  of  experiments  regarding  birch-tar  oil         .  358 


PART  II. 
MANUFACTURE  OF  CIDERS,  FRUIT  WINES,  ETC. 

CHAPTER    XXVII. 

INTRODUCTION. 

Definition  of  the  term  wine;  Ingred  ents  which  are  added  to  artificial  wines; 
Ripening  of  fruits         ...........  360 

Occurrence  and  behavior  of  pectose;  Formation  and  properties  of  pectine      .   3(51 
Properties  of  metapectine;  Constitution  and  action  of  pectose         .         .         .  302 
Pectous  fermentation;  Formation  and  properties  of  pectic  acid         .         .      .   363 
Formation  of  metapectic  acid;  Definition  of  the  term  isomeric         .         .      .  304 
Development  and  ripening  of  a  fruit  viewed  as  a  chemical  process;  Results 
of  chemical  researches  into  the  changes  fruits  undergo  during  their  devel- 
opment and  perfection         ..........  365 

Stages  a  fruit  passes  through  during  development  and  ripening         .         .      .  307 

CHAPTER  XXVIII. 

FRUITS  AND  THEIR  COMPOSITION. 

Fruits  used  for  the  preparation  of  fruit  wines;  Table  of  the  average  percen- 
tage of  sugar  in  different  varieties  of  fruit         .          .         .          ...  308 

Tables  of  the  average  percentage  of  free  acid  expressed  in  malic  acid,  and 
of  the  proportion  between  acid,  sugar,  pectine,  gum  etc.,  and  of  the  pro- 
portions between  water,  soluble  and  insoluble  substances         .         .         .     .  309 

Tables  of  the  composition  of  the  juice  according  to  the  content  of  sugar,  pec- 
tine, etc.,  and  of  the  content  of  five  acid    .......   370 

Urape  sugar  or  glucose;  Acids 371 

Albuminous  substances;  Pectous  substances;  Gum  and  vegetable  mucilage     .   372 
Tannin;  Pathological  and  physiological  tannins   ......  373 

Inorganic  constituents;  Fermentation  ........  374 


XX  CONTENTS. 


Chief  products  of  vinous  fermentation  .         .         .         .         .         .         .         .  375 

Succinic  acid;  Glycerin        ..........   376 

Carbonic  acid;  Alkaloid  in  wine  .........   377 

CHAPTER  XXIX. 
MANUFACTURE  OF  CIDER. 

Methods  of  obtaining  the  juice  or  must  from  the  fruit;  W.  O.  Hickock's 

portable  cider  mill    .         .         .         .         .         .         .                   .         .         .  378 

Crushing  mill;  Davis's  star  apple  grinder 379 

Presses 880 

Farmer's  cider  press   ...........  381 

Extra-power  cider  press       ..........  382 

Revolving  platform  of  the  extra-power  cider  press;  Improved  racks       .         .  383 

Plain  racks 384 

Apple  elevator    ............  385 

Arrangement  of  a  plant  for  making  cider  on  a  large  scale     ....  3£6 

Testing  the  must  as  to  the  content  of  acid  and  sugar;  Determination  of  acid.  387 

Determination  of  sugar        ..........  389 

Glucose 390 

Determination  of  the  content  of  pure  sugar  in  glucose  .....  391 

Anthon's  table  for  finding  the  content  of  anhydrous  sugar  in  saturated  solu- 
tions of  glucose;  Cider  from  apples    ........  392 

Type  of  composition  for  pure  ciders;  Analyses  of  ciders  by  the  United  States 

Agricultural  Department          .........  393 

Choice  of  varieties  of  apples  for  making  cider       ......  394 

Composition  of  the  apple 395 

Juice  constituents  of  the  apple;  Gathering  and  sweating  apples  for  the  pre- 
paration of  cider      .         .         .         .         .         .         .         .         .         .         .  396 

Reduction  of  the  apples  to  an  impalpable  pulp;   Diversity  of  opinion  as  re- 
gards the  crushing  of  the  seeds          ........  397 

Pressing;  Primitive  method  of  laying  the  cheese;  Substitution  of  hair  cloth 

and  cotton  press-cloth  for  straw  in  laying  the  cheese.         ....  398 

Extraction  of  the  juice  by  diffusion;  Objections  urged  against  pasteurizing 
or  sterilizing  fresh  apple  juice;  H.  C.  Gore's  experiments  to  develop  a 

method  for  sterilizing  apple  juice     ........  399 

Conclusions  arrived  at  regarding  the  carbonating  of  fresh  apple  juice;  Addi- 
tion of  benzoate  of  soda  to  apple  juice  sold  in  bulk;  H.  C.  Gore's  investiga- 
tions of  the  cold  storage  of  cider       ........  401 

Testing  apple  juice  to  be  fermented;  Filling  the  fermentation  casks       .         .  402 

Fermentation  of  the  apple  juice,  and  pure  cultures  of  yeast  for  this  purpose.  403 

Fermentation  funnel  or  ventilating  funnel    .......  404 

First  or  tumultuous  fermentation.          ........  405 

Clarification  of  cider    ...........  106 

Additions  to  cider  intended  for  export.         .......  407 

Preparation  of  cider  in  the  same  manner  as  other  fruit  wines;  Red  apple  wine 

or  red  wine  from  cider  ;  Dr.  Denis  Dumont's  directions  for  bottling  cider  .  408 


CONTENTS.  XXI 

PAGE 

Manufacture  of  cider  in  the  island  of  Jersey.         .         .         .         .         .         .   409 

Devonshire  cider.         .         .         .         .         .         .         .         .         .         .         .410 

Cider  as  a  basis  for  artificial  wines        ........   411 

Burgundy;  Malaga  wine;  Sherry  wine;  Diseases  of  cider      .         .         .         .412 

Acidity  in  cider;  Viscosity  or  greasy  appearance  of  cider     .         .         .         .413 

Turbidity  or  lack  of  clarification  of  cider;  Adulteration  of  cider;  Minimum 
for  the  composition  of  pure  cider       ...         .         .         .         .         .         .  414 

Manufacture  of  brandy  from  cider         ........  415 

Preparation  of  the  juice  for  distillation;  Brandy  from  plums,  damsons,  etc.  416 

Distillation 417 

Pear  cider;  Preparation  of  "  port  wine  "  from  cider  .....  418 
Quince  wine  ............  419 

CHAPTER  XXX. 
PREPARATION  OF  FRUIT  WINES. 

From  small  fruits;  Means  of  preventing  the  wine  from  turning  .  .  .  419 
Advantage  of  using  a  mixture  of  various  juices;  Means  of  improving  the  flavor 

and  keeping  qualities  of  the  wine     ........  420 

Selection  of  the  fruit;  Expression  of  the  juice;  Fermentation;  Clarification 

and  drawing,  off  into  bottles       .........  421 

Currant  wine       ............  422 

Strawberry  wine.          ...........  424 

Gooseberry  wine.          ...........  425 

•Gooseberry  champagne         ..........  427 

Raspberry  wine  .         .         .         .         .         .         .         .         .         .         .         .  429 

Blackberry  wine 430 

Mulberry  wine;  Elderberry  wine;  Juniperberry  wine  .  .  .  .  .  431 
Rhubarb  wine;  Parsnip  wine;  Wine  from  various  materials.  .  .  .  432 
From  stone  fruits;  Cherry  wine;  Morello  wine;  Plum  wine  ....  433 
Sloe  or  wild  plum  wine 434 


PART  III. 

CANNING  AND  EVAPORATING  OF  FRUIT;  MANUFACTURE 
OF  CATSUPS;  FRUIT  BUTTERS,  MARMALADES, 
JELLIES,  PICKLES  AND  MUSTARDS;  PRESER- 
VATION OF  MEAT,  FISH  AND  EGGS. 

CHAPTER  XXXI. 

PRESERVATION  OF  FRUIT. 

Rules  applying  to  all  methods  of  preserving  fruit 435 

French  method  known  as  Baine-Marie;  Preservation  of  the  flesh  of  the  fruit 
without  boiling.          .         .         ......         ...  436 


XX11  CONTENTS. 

PAGE 

Preparation  of  the  fruit  for  preserving;  Preservation  of  fine  table  pears;  Pre- 
servation in  air-tight  cans.          .........  438 

Groups  of  canned  articles  embraced  in  the  American  trade  lists;  Fruits  suit- 
able and  unsuitable  for  canning 439 

Various  styles  of  cans  and  jars       .........  440 

Manner  of  coating  and  lining  the  inside  of  tin  cans;  Manufacture  of  tin  cans 

in  the  United  States  canneries 441 

Division  of  labor  in  the  canneries;  Preparation  of  the  syrup.         .         .         .  442 

Apparatus  for  the  expulsion  of  the  air  by  heating  the  cans;  Cleansing  and 
testing  the  cans.         ...........  443 

Canning  of  tomatoes;  Selection  of  a  site  for  a  canning  establishment      .         .  445 
How  contracts  for  a  supply  of  tomatoes  are  made;  Arrangement  of  a  canning 
factory;  Scalding  the  tomatoes  .........  446 

Skinning  the  tomatoes;   Machines  for  filling  the  cans;  Cappers  and  their 

work .         .         .         .         .         .         .  447 

Labeling  the  cans.         .........          .  448 

Trials  and  vexations  of  a  canner's  life;  Catchup     ......  449 

Tomato  catchup     ............  450 

Walnut  catchup    ............  451 

Gooseberry  catchup;    Horseradish  catchup  ;    Fruit  butter,  marmalades  and 
jellies;  Fruit  butter;  Manufacture  of  apple  butter     .....  453 

Preparation  of  raisine  ;  Marmalade      ........  454 

Derivation  of  the  wood  marmalade;  Manufacture  of  marmalade  on  a  large 
scale.          .............  455 

Quantity  of  sugar  to  be  used;  Secret  of  the  great  reputation  the  products  of 

the  principal  American  factories  enjoy;  Selection  of  fruit  for  marmalade   .  456 
Apple  pulp  as  a  foundation  for  marmalade,  and  its  preparation;  Storage  of 

fruit  pulp 457 

Tutti-frutti;   English  marmalade;   Jelly;   Erroneous  opinion  regarding  the 

quantity  of  sugar  required  in  making  jelly;  Apple  jelly  without  sugar       .  458 
Use  of  the  saccharometer  in  jelly  boiling;  Jellies  from  pears,  mulberries  and 

other  small  fruit 459 

Preparation  of  jelly  from  stone-fruit,  quinces,  rhubarb,  etc  ;  French  perfumed 

jelly 460 

Manufacture  of  apple  jelly  in  one  of  the  largest  plants  for  that  purpose;  Ar- 
rangement of  the  factory 461 

Grating  the  apples  and  expressing  the  juice;  The  defecator  and  its  object      .  462 
The  evaporator      ............  463 

Proper  consistency  for  perfect  jelly;  Yield  of  jelly  from  a  bushel  of  fruit       .  464 
Saving  of  the  apple  seeds       ..........   465 

CHAPTER  XXXII. 

EVAPORATION  OF  FRUIT. 
The  Alden  Patent  for  evaporating  fruit.         .......  465 

Theory  of  evaporating  fruit 466 


CONTENTS.  XX111 


Absorption  of  moisture  by  the  air.         ........  467 

lieason  why  drying  fruit  in  the  oven  must  yield  unsatisfactory  results  .         .  468 
Chemical  analysis  of  a  parcel  of  Baldwin  apples,  showing  the  changes  in  the 

composition  of  the  fruit  by  drying  in  the  oven,  and  by  evaporation  .         .  4('9 
Tower  evaporators;  The  improved  Alden  evaporator     .....  470 

The  Williams  evaporator      .         .         .         .         .         .    *   .         .         .         .  472 

Manner  of  operating  the  Alden  evaporator    .......  474 

Table  of  intervals  of  time  at  which  the  trays  must  be  placed  in  the  evapora- 
tor; Handling  and  packing  the  evaporated  fruit 475 

Kiln  evaporators,  described  by  H.  T.  Gould;  Construction  of  a  kiln     .         .  476 
Heating  the  kiln  and  appliances  for  that  purpose         .         .         .         .          .  477 

Arrangement  of  an  evaporator  having  four  or  five  kilns         ....  479 

Selection  of  the  varieties  of  fruit  to  be  evaporated;  Paring  and  bleaching  ap- 
ples; Types  of  bleachers        ..........  480 

Temperature  to  be  maintained  in  the  kiln         .......  481 

Manner  of  placing  the  fruit  in  the  trays  when  drying  in  the  tower  evapora- 
tor; Treatment  of  plums  after  evaporating;  Conversion  of  grapes  into  rais- 
ins; Mode  of  obtaining  Malaga  grapes;  Evaporation  of  tomatoes        .         .  482 
Evaporation  of  various  vegetables,  and  of  potatoes         .....  483 

Sun-drying  apparatus         ...........  484 

French  method  of  drying  fruit  in  the  oven         ...         ....  485 

CHAPTER  XXXIII. 
PREPARATION  OF  PICKLES  AND  MUSTARD. 

Pickles;  Manner  of  packing  pickles;  General  rule  for  the  preparation  of  pick- 
les         487 

Preparation  of  spiced  vinegar         .........  488 

"Greening"  pickles;  Fruits  and  vegetables  chiefly  used  for  the  preparation 
of  pickles 489 

Mixed  pickles;    Picalilli;  Pickled  gherkins         .          ...          .         .  490 

Gherkins  in  mustard;  Pickled    mushrooms;  Pickled  onions,  peaches,  peas, 
and  tomatoes         ............  491 

Pickled  walnuts;  Mustard;  English  method  of  preparing  mustard;  Substan- 
ces used  for  seasoning  mustard         .........  492 

Gumpoldskircher  must-mustard;  Moutarde  des  Jesuites,  French   mustard; 
Ordinary  mustard         ...........   493 

Frankfort  mustard;  Wine  mustard;  Aromatic  or  hygienic  mustard;  Diissel- 
dorf  mustard;  Sour  Diisseldorf  mustard         .......  494 

Sweet  and  sour  Kremser  must-mustards;  Moutarde  de  maille;  Moutarde  aux 
Apices;  Moutarde  aromatisee;  English  mustard.         .....  495 

CHAPTER  XXXIV. 

PRESERVATION  OF  MEAT.  FISH,  AND  EGGS. 

Appert's  method  of  canning  meats;  Cans  used;  Placing  the  prepared  meats  in 
the  cans;  Heating  the  cans  and  steam-chamber  for  the  purpose  .         .         .  496 


XXIV  CONTENTS. 

PAGE 

Object  to  be  attained  in  operating  according  to  Appert's  method   .         .         .  497 
Preparation  of  corned  beef  according  to  Appert's  method;  Meat  biscuit  ac- 
cording to  Gallamond        ..........  498- 

Soup  tablets 499 

Beef  extract;  Quick  salting  of  meat  by  liquid  pressure;  Quick  process  of 

smoking  meat  ^ 500 

Preparation  of  powdered  meat;  Preservation  of  fish 502 

Preservation  of  eggs     .          ..........  503 


APPENDIX. 

Table  I.     Hehner's  alcohol  table.          . 506 

Table  II.,  which  indicates  the  specific  gravity  of  mixtures  of  alcohol  and 
water * 509 

Table  III.  Proportion  between  the  per  cent,  by  weight  and  by  volume  of 
alcoholic  fluids  at  59°  F 510 

Table  IV.  The  actual  content  of  alcohol  and  water  in  mixtures  of  both  fluids 
and  the  contraction  which  takes  place  in  mixing  .....  511 

Table  V.  For'comparing  the  different  aerometers  with  Tralles's  alcoholo- 
meter   512 

Determination  of  the  true  strengths  of  spirit  for  the  standard  temperature  of 
59°  F 5ia 

Table  VI.  Determination  of  the  true  strengths  of  spirit  for  the  standard 
temperature  of  59°  F.  (15°  C.). 514 

Explanation  of  Table  VI 519 

Table  VII.  Determination  of  the  true  volume  of  alcoholic  fluids  from  the 
apparent  volume  at  different  temperatures;  Explanation  of  Table  VII.  ,  520 

Table  VIII.  Preparation  of  whiskey  of  various  strengths  from  spirits  of 
wine.  ...  t  .........  522 

Table  IX.     For  the  reduction  of  specific  gravities  to  saccharometer  per  cent.  523 

Table  X.     Comparative  synopsis  of  the  aerometers  for  must  generally  used  .  526 

Table  XL     Table  to  Oechsle's  aerometer  for  must 527 

Table  XII.     Table  to  Massonfour's  aerometer  for  must 527 

Table  XIII.  For  comparing  per  cent,  of  sugar  with  per  cent  of  extract  and 
specific  gravity 527 

Table  XIV.  For  determining  the  content  of  per  cent  of  acetic  acid  contained 
in  a  vinegar  of —  specific  gravity  (according  to  A.  C.  Oudemans)  .  .  528 

Table  XIV.  For  determining  the  content  of  per  cent,  of  acetic  acid  con- 
tained in  a  vinegar  of —  specific  gravity  (according  to  Mohr)  .  .  .  529 

Table  XVI.  Comparison  of  the  scales  of  Keaumur's,  Celsius's  and  Fahren- 
heit's thermometers 530 

Index   .  .  531 


PART  I. 

VINEGAR. 


CHAPTER  I. 

INTRODUCTORY  AND  HISTORICAL. 

Ordinary  vinegar  consists  of  a  weak  solution  of  acetic  acid 
in  aqueous  fluids  prepared  by  the  oxidation  of  alcoholic  liquors 
by  means  of  acetic  acid  bacteria,  Bacterium  aceti,  of  which 
there  are  many  varieties,  the  best  races  being  propagated  by 
pure  culture  methods,  and  used  for  impregnating  the  alcoholic 
liquors  to  be  fermented.  The  color  of  vinegar  and,  to  a  cer- 
tain extent,  also  its  odor  and  taste  are  influenced  by  the  ma- 
terials from  which  it  is  prepared.  In  this  form  it  has  been 
known  from  the  earliest  times,  and  it  must  have  been  used 
contemporaneously  with  wine,  because  it  is  evident  that  at  the 
temperature  of  the  Eastern  countries,  where  the  first  .experi- 
ments with  the  juice  of  the  grape  were  made,  fermentation 
must  have  set  in  rapidly  and  the  wine  been  quickly  trans- 
formed into  an  acid  compound.  Vinegar  is  mentioned  in  the 
Old  Testament,  and  Hippocrates  made  use  of  it  as  a  medicine. 
That  the  solvent  effects  of  vinegar  were  understood  by  the 
ancients,  is  shown  by  the  well-known  anecdote  of  Cleopatra, 
related  by  Pliny.  To  gain  a  wager  that  she  could  consume 
at  a  single  meal  the  value  of  a  million  sesterces,  she  dissolved 
pearls  in  vinegar  which  she  drank.  This  is  also  shown  by 
the  equally  well  known,  but  exaggerated  account  by'Livy  and 
Plutarch,  that  Hannibal  overcame  the  difficulties  offered  by 


2  MANUFACTURE    OF    VINEGAR. 

the  rocks  to  the  passage  of  his  army  over  the  Alps,  by  dissolv- 
ing them  with  vinegar.  Admitting  the  exaggeration,  or  the 
explanation  which  some  give,  viz.:  that  Hannibal  used  the 
vinegar  by  way  of  strategem,  to  incite  his  men  to  greater  ex- 
ertion by  the  belief  that  the  difficulties  of  the  path  were 
diminished,  the  case  nevertheless  shows  that  the  solvent  action 
of  vinegar  upon  certain  substances  was  well  known  at  that 
period. 

Vitruvius  also  states  that  rocks  which  cannot  be  attacked 
by  either  fire  or  iron,  will  yield  when  heated  and  wet  with 
vinegar. 

Although  there  can  be  no  doubt  that  vinegar  was  in  very 
general  use  at  an  early  period,  there  was  no  definite  knowledge 
as  to  the  cause  of  its  production  and  the  mode  of  its  formation, 
and  we  are  indebted  to  the  much-abused  alchemists  for  the 
first  knowledge  of  its  purification  and  concentration  by  dis- 
tillation. 

Gerber,  who  flourished  in  the  eighth  century,  gives  us  the 
earliest  description  of  the  process  of  increasing  the  strength  of 
wine-vinegar  by  distillation,  and  Albucases,  about  1100,  stated 
the  fact  that  vinegar  to  be  colorless  has  to  be  distilled  over  a 
moderate  fire.  Basilius  Valentinus,  a  monk  and  celebrated 
alchemist  of  the  fifteenth  century,  knew  that  by  the  slow  dis- 
tillation of  vinegar,  first  a  weak,  and  then  a  stronger  product 
is  obtained,  and  he  was  probably  also  acquainted  with  the 
process  of  obtaining  strong  acetic  acid  by  distilling  cupric  ace- 
tate (verdigris.)  In  fact,  for  a  long  time  this  was  the  only  way 
of  preparing  acetic  acid,  the  result  of  the  further  rectification  of 
the  product  being  termed  radical  vinegar,  spiritus  Veneris, 
Venus' s  vinegar,  spiritus  aeruginis,  etc. 

Stael,  in  1697,  strengthened  vinegar  by  freezing  out  some  of 
its  water.  In  1702,  he  taught  the  method  of  obtaining  strong 
acetic  acid  by  neutralizing  vinegar  by  an  alkali,  and  distilling 
the  acetate  thus  formed  with  oil  of  vitriol.  The  Count  de 
Laragnais  (1759),  and  the  Marquis  de  Courtenvaux  (1768), 
showed  that  the  most  concentrated  acetic  acid  obtained  from 


INTRODUCTORY    AND    HISTORICAL.  3 

verdigris  was  capable  of  crystallization.  Loewitz  (1789) 
taught  how  pure,  but  weak  acetic  acid  might  be  strengthened 
by  passing  it  repeatedly  over  charcoal  powder.  It  may  thus 
be  deprived  of  so  much  of  its  water  that  it  crystallizes  by  cold. 
This  crystallizable  acetic  acid  is  the  strongest  which  it  is  pos- 
sible to  obtain.  Durande  (1777),  gave  to  it  the  name  which 
it  still  bears,  of  glacial  acetic  acid. 

The  formation  of  an  acid  body  in  the  destructive  distillation 
of  wood  was  known  as  early  as  the  seventeenth  century.  How- 
ever, it  was  for  a  long  time  not  recognized  as  acetic  acid,  but 
considered  a  special  acid  (pyroligneous  acid).  Fourcroy  and 
Vauquelin,  in  1800,  were  the  first  to  recognize  this  acid  as 
acetic  acid,  and  Thenard,  in  1802,  demonstrated  the  presence 
of  acetic  acid  among  the  products  formed  in  the  destructive 
distillation  of  animal  substances. 

Berzelius,  in  1814,  determined  the  exact  chemical  constitu- 
tion of  acetic  acid,  and  Saussure,  in  the  same  year,  that  of  alco- 
hol. Dr.  J.  Davy  observed  that  spongy  platinum,  in  contact 
with  vapor  of  alcohol,  became  incandescent  and  generated 
acetic  acid.  Dobereiner  further  studied  the  nature  of  the  acid, 
and  proved  that  the  alcohol  was  oxidized  at  the  expense  of  the 
atmospheric  air,  producing  acetic  acid  and  water,  and  that  no 
carbonic  acid  was  formed,  thus  pointing  out  the  fallacy  of  the 
opinion  held  by  the  chemists  of  his  time  that  carbonic  acid 
was  one  of  the  products  of  acetic  fermentation. 

Schiitzenbach,  in  1823,  one  year  after  the  establishment  by 
Dobereiner  of  the  now  generally  accepted  theory  of  the  forma- 
tion of  acetic  acid  from  alcohol,  introduced  the  quick  process 
of  manufacturing  vinegar. 

Without  detracting  from  the  credit  due  to  Schiitzenbach  for 
the  introduction  of  his  method  and  the  improvement  in  the 
process  of  manufacturing  vinegar,  it  may  be  mentioned  that  as 
early  as  1732,  nearly  a  century  before,  the  celebrated  Dutch 
chemist  and  physician,  Boerhave,  made  known  a  method  for 
making  vinegar  from  wine,  which  contained  the  principles  of 
the  quick  process. 


4  MANUFACTURE    OF    VINEGAR. 

Although  it  is  now  more  than  ninety  years  since  the  intro- 
duction of  Schiitzenbach's  process  into  practice,  the  manufac- 
ture of  vinegar  from  alcohol  remains  nearly  the  same.  While 
no  change  can  be  made  as  regards  the  theoretical  part  of  the 
process,  it  being  erected  on  a  foundation  clearly  indicated  by 
a  knowledge  of  natural  laws,  many  important  improvements 
may  surely  be  introduced  in  the  manufacture  of  vinegar  on  a 
large  scale,  this  being  especially  the  case  where  it  is  uninter- 
ruptedly carried  on  with  the  use  of  suitable  apparatus.  Many 
manufacturers  still  work  according  to  Schiitzenbach's  original 
plan,  i.  e.,  they  use  an  ^immense  amount  of  labor  for  a  per- 
formance which  can  be  attained  in  a  much  simpler  manner. 

Progress  is  essential  in  every  business,  but  for  several  reasons 
it  is  especially  necessary  for  the  manufacturer  engaged  in  mak- 
ing vinegar  by  the  quick  process.  Alcohol  in  every  form — 
whiskey,  beer,  wine — is  everywhere  subjected  to  a  high  tax,  and 
the  constantly  increasing  taxation  of  this  fundamental  material 
for  the  manufacture  of  vinegar,  of  course  increases  the  price 
the  manufacturer  has  to  pay  for  it.  Another  reason  why  the 
production  of  vinegar  from  alcohol  becomes  constantly  more 
difficult  is  found  in  the  great  competition  arising  from  the 
continued  improvements  in  the  manufacture  of  pure  acetic 
acid  from  wood.  Not  many  years  ago  it  was  considered  im- 
possible to  obtain  entirely  pure  acetic  acid  from  wood  when 
manufacturing  on  a  large  scale,  but  the  article  produced  at 
the  present  time  may  be  almost  designated  as  "  chemically 
pure "  in  the  true  sense  of  the  word,  it  containing,  besides 
acetic  acid,  only  water,  and  the  most  accurate  analysis  cannot 
detect  a  trace  of  the  products  of  tar,  which  render  unpurified 
wood  vinegar  unfit  for  use. 

For  consumption  on  a  large  scale,  especially  where  only  a 
body  of  an  acid  taste  is  required,  the  use  of  so-called  "  vinegar 
essence,"  i.  e.,  pure  80  to  90  per  cent,  acetic  acid,  obtained  from 
wood,  and  which,  when  properly  diluted,  furnishes  ordinary 
vinegar,  will  undoubtedly  gradually  supersede  vinegar  pre- 
pared from  alcohol,  it  being  considerably  cheaper.  And  not- 


INTRODUCTORY    AND    HISTORICAL.  5 

withstanding  that  the  price  of  wood  vinegar  is  declining  every 
year,  in  regions  where  wood  is  plentiful  and  cheap  its  manu- 
facture is  a  remunerative  industry  on  account  of  the  many 
valuable  by-products — tar,  wood  spirit,  charcoal — obtained 
besides  acetic  acid.  At  the  present  time,  for  all  industrial  pur- 
poses where  acetic  acid  is  required,  as  for  instance  in  the  man- 
ufacture of  tar  colors,  that  obtained  from  wood  is  used,  and 
the  quantities  consumed  in  the  production  of  vinegar  for  do- 
mestic purposes  becomes  larger  every  year. 

But  the  manufacture  of  vinegar  from  alcohol  and  alcoholic 
liquids  will  nevertheless  continue  to  flourish,  because  the  pro- 
duct obtained  from  them  possesses  different  properties  from 
the  pure  acetic  acid  prepared  from  wood.  Vinegar  obtained 
from  alcohol,  and  still  more  so  that  from  fermented  fruit  juices, 
such  as  wine,  cider,  skins  of  pressed  grapes,  or  from  malt,  con- 
tains, besides  acetic  acid  and  water,  small  quantities  of  bodies 
which,  on  account  of  their  being  analogous  to  those  occurring 
in  wine,  may  be  designated  as  "  bouquet  bodies,"  and  which 
give  to  the  vinegar  an  agreeable  smell  and  taste  entirely  want- 
ing in  acetic  acid  prepared  from  wood.  These  properties  are 
so  characteristic  that  any  one  gifted  with  a  sensitive  and  prac- 
ticed sense  of  smell  can  at  once  distinguish  pure  acetic  acid 
vinegar  from  that  prepared  from  wine,  cider,  beer,  etc. 

By  the  addition  of  volatile  oils  or  compound  ethers  an  agree- 
able odor  may,  of  course,  be  imparted  to  vinegar  obtained  by 
diluting  pure  wood  acetic  acid  with  water,  but  it  is  impossible 
to  produce  the  harmonious  bouquet  peculiar  to  vinegar  pre- 
pared from  alcohol  or  fruit  juices,  a  similar  relation  existing 
here  as  between  genuine  and  artificial  wine.  The  latter  may 
be  made  so  that,  as  regards  taste  and  smell,  it  nearly  ap- 
proaches genuine  wine,  but  a  connoisseur  will  at  once  detect 
the  difference. 

The  principal  defects  of  the  manner  of  manufacturing  vine- 
gar by  the  quick  process  in  general  use  are  not  in  the  method 
itself,  for  that,  as  already  indicated,  corresponds  entirely  to  the 
theoretical  conditions,  and  yields  as  good  a  product  as  can  be 


6  MANUFACTURE    OF    VINEGAR. 

obtained  from  the  raw  material  used.  The  weak  point  of  the 
process  is  found  in  practical  execution  of  it,  the  losses  of 
material  being  much  more  considerable  and  greater  than 
absolutely  necessary  :  the  consumption  of  labor  is  large,  and,  as 
every  manufacturer  knows  from  experience,  interruptions  in  the 
regular  process  of  working  are  of  too  frequent  occurrence. 

All  these  disadvantages  can  be  reduced  to  a  minimum,  if  not 
absolutely  overcome,  and  it  is  hoped  sufficient  hints  how  this 
can  be  done  will  be  found  in  the  following  chapters. 

As  will  be  explained  later  on  acetic  acid  contains  the  same 
elements  found  in  carbonic  acid  and  water,  and  to  judge  from 
the  results  already  attained  by  chemistry  in  building  up  com- 
pounds from  their  elements,  a  method  will  no  doubt  be  found 
by  which  acetic  acid  can  on  a  large  scale  be  produced  from  its 
elements.  It  is  difficult  to  predict  the  effect  the  discovery  of 
such  a  process  would  have  upon  the  life  of  all  other  methods 
of  vinegar  manufacture.  In  fact,  acetic  acid  has  already  been 
prepared  in  this  manner,  but  the  method  employed  is  not 
adapted  for  operations  on  a  large  scale. 


CHAPTER  II. 

THEORY    OF    THE    FORMATION    OF    VINEGAR. 

INDEPENDENT  of  the  formation  of  acetic  acid  by  destructive 
distillation,  the  chemical  processes  by  which  acetic  acid  in 
larger  quantities  is  formed  are  at  present  quite  well  understood, 
and  may  be  briefly  explained  as  follows : 

As  previously  mentioned,  Dobereiner,  in  1822,  established 
the  theory  of  the  formation  of  acetic  acid  from  alcohol,  and  the 
processes  taking  place  thereby  may  be  expressed  by  the  fol- 
lowing formula  : 

C2H60  +  02  =  C2H402  +  H20 

Alcohol.      Oxygen.      Acetic  acid.        Water. 


THEORY    OF    THE    FORMATION    OF    VINEGAR.  7 

According  to  the  above  formula,  acetic  acid  and  water  are 
formed  by  the  action  of  oxygen  upon  alcohol,  and  hence  the 
formation  of  acetic  acid  takes  place  by  a  partial  combustion  or 
oxidation  of  the  latter.  Alcohol  and  acetic  acid  are,  however, 
only  two  members  of  the  process,  and  that  besides  them  other 
bodies  are  formed  from  the  alcohol,  can  in  a  vinegar  manufac- 
tory be.  readily  detected  by  the  sense  of  smell. 

By  treating  alcohol  with  pyrolusite  and  sulphuric  acid — 
hence  by  the  action  of  oxygen  at  the  moment  of  its  liberation 
from  a  combination,  i.  e.,  in  its  nascent  state — Dobereiner  ob- 
tained a  body  which  he  called  "  light  oxygenated  ether " 
(leichter  Sauerstoffather).  Liebig  later  on  studied  this  com- 
bination more  accurately,  and  found  that,  as  regards  its  com- 
position, it  differed  from  that  of  alcohol  only  by  containing  two 
atoms  less  of  hydrogen.  He  applied  to  it  the  term  ''alde- 
hyde." Aldehyde  is  composed  of  C2H40,  and  its  formation  is 
represented  by  the  formula — 

C2H60  +  02  =  C2H402  +  H20 

Alcohol.      Oxygen.        Aldehyde.         Water. 

In  the  examination  of  the  properties  of  aldehyde  it  was 
shown  that  it  is  readily  converted  into  acetic  acid  by  the  ab- 
sorption of  oxygen  and,  based  upon  these  facts,  Liebig  estab- 
lished a  theory  of  the  formation  of  vinegar  which  was  for  many 
years  considered  correct. 

Essentially  Liebig's  theory  is  as  follows :  By  the  exposure, 
under  suitable  conditions,  of  alcohol  to  the  action  of  the  atmos- 
pheric oxygen,  one-third  of  the  entire  quantity  of  hydrogen 
contained  in  it  is  withdrawn,  and  aldehyde  is  formed.  The  lat- 
ter, however,  immediately  combines  further  with  oxygen,  and 
is  converted  into  acetic  acid  ;  the  formation  of  vinegar  from 
alcohol  being,  therefore,  a  partial  process  of  combustion. 

From  the  present  standpoint  of  our  knowledge  regarding  the 
formation  of  acetic  acid  from  alcohol,  the  correctness  of  this 
theory  is  about  parallel  with  that  according  to  which  alcohol 
and  carbonic  acid  are  formed  by  the  alcoholic  fermentation  of 


8  MANUFACTURE    OF    VINEGAR. 

sugar.  The  latter  process  can  also  be  illustrated  by  an  equa- 
tion in 'as  simple  a  manner  as  the  conversion  of  alcohol  into 
acetic  acid  by  aldehyde.  At  the  present  time,  the  processes 
taking  place  in  the  formation  of  acetic  acid  from  alcohol  must, 
however,  be  considered  as  far  more  complicated  than  supposed 
by  Liebig.  According  to  the  latter,  a  simple  oxidation,  i.  e.,  a 
simple  chemical  process,  takes  place.  But,  according  to  the 
now  universally  accepted  view,  the  formation  of  vinegar  is  due 
to  a  chemico-physiological  process  with  the  co-operation  of  a 
living  organism.  Alcohol  and  oxygen  alone  do  not  suffice  for 
this  purpose,  the  presence  of  nitrogenous  bodies  and  salts,  be- 
sides that  of  an  organism,  being  absolutely  necessary. 

The  French  chemist,,  Pasteur,  was  the  first  to  establish  the 
formation  of  vinegar  as  a  peculiar  process  of  fermentation,  and 
he  maintains  that  a  certain  organism,  the  "  vinegar  ferment" 
or  "  vinegar  yeast,"  consumes  the  alcohol,  nitrogenous  sub- 
stances and  salts,  and  separates  acetic  acid,  aldehyde,  etc., 
as  products  of  the  change  of  matter  taking  place  in  the  living 
organism.  On  the  other  hand,  the  German  chemist  Niigeli  is 
of  the  opinion  that  the  role  of  the  organism  is  to  bring  the 
particles  of  the  substance  to  be  fermented — in  this  case  alcohol 
— lying  next  to  it,  into  such  vibrations  as  to  decompose  them 
into  more  simple  combinations — in  this  case,  acetic  acid, 
aldehyde,  etc. 

The  scientific  dispute  over  these  two  different  views  is  not 
yet  settled,  though  the  majority  of  chemists  are  inclined  to 
accept  Pasteur's  theory.  For  the  practical  man  it  is  of  no 
consequence  which  of  these  views  will  be  finally  accepted  as 
the  correct  one;  the  fact  that  the  process  of  the  formation  of 
vinegar  is  connected  with  the  living  process  of  an  organism 
being  alone  of  importance  to  him. 

As  is  well  known,  organisms  producing  fermentation  are 
named  after  certain  products  which  they  form  in  larger  quan- 
tities, the  organisms  forming  alcohol  from  sugar  being,  for  in- 
stance, briefly  termed  "alcoholic  ferment."  In  this  sense  we 
may  also  speak  of  a  vinegar  or  acetic  ferment,  since  a  definite 


THEORY    OF    THE    FORMATION    OF    VINEGAR. 

organism  causing  the  formation  of  larger  quantities  of  acetic 
acid  from  alcohol  is  known,  and  the  cultivation  of  this  ferment 
is  one  of  the  principal  tasks  of  the  manufacturer  of  vinegar. 

Numerous  observations  have  established  the  fact  that  the 
properties  of  forming  large  quantities  of  acetic  acid  are  inher- 
ent only  in  this  ferment.  Small  quantities  of  acetic  acid  are, 
however,  also,  constantly  formed  by  other  ferments,  so  that 
in  examining  products  due  to  the  process  of  decomposition 
induced  by  organisms,  acetic  acid  will  generally  be  found 
among  them.  In  the  alcoholic  fermentation,  at  least  in  that 
of  wine  and  bread  dough,  acetic  acid  is  always  found.  It 
originates  in  the  germination  of  many  seeds,  and  generally 
appears  in  the  putrefaction  of  substances  rich  in  nitrogen,  such 
as  albumen,  glue,  etc.  It  appears  also  in  the  so-called  lactic 
fermentation,  the  lactic  acid  formed  by  the  specific  ferment  of 
this  species  of  fermentation  being  by  farther  processes  of  fer- 
mentation decomposed  into  butyric  and  acetic  acids. 

Acetic  acid  is  found  in  many  animal  juices,  for  instance,  in 
meat  juices,  milk,  sweat  and  urine.  It  also  occurs  in  the 
fresh  fruit  of  the  tamarind.  The  processes  which  take  place 
in  its  formation  in  these  cases  are  not  known,  though  it  is 
very  likely  directly  formed  from  certain  varieties,  of  sugar. 

There  is  quite  a  large  series  of  X'hemical  processes  in  which 
certain  quantities  of  acetic  acid  are  formed.  Sugar,  starch, 
woody  fibre  and,  in  general,  all  compounds  known  as  carbo- 
hydrates, when  fused  with  caustic  alkalies,  yield  certain  quan- 
tities of  acetic  acid,  and  also  by  themselves  when  subjected  to 
destructive  distillation.  Among  the  processes  by  which  acetic 
acid  is  produced  in  a  purely  chemical  manner,  i.  e.,  without 
the  co-operation  of  organisms,  the  most  interesting  is  that  by 
which  its  formation  is  effected  by  the  action  of  very  finely 
divided  platinum,  the  so-called  platinum  black,  upon  alcohol. 
Platinum  black  is  readily  prepared  by  boiling  a  solution  of 
platinic  chloride,  to  which  an  excess  of  sodium  carbonate  and 
a  quantity  of  sugar  have  been  added,  until  the  precipitate 
formed  after  a  little  time  becomes  perfectly  black,  and  the 


10 


MANUFACTURE    OF    VINEGAR. 


FIG.  1. 


supernatant  liquid  colorless.  The  black  powder  is  collected 
on  a  filter,  washed  and  dried  by  gentle  heat.  On  account  of 
the  minute  state  of  its  division,  this  substance  condenses  within 
it  several  hundred  times  its  volume  of  oxygen,  and  conse- 
quently when  the  vapor  of  alcohol  comes  in  contact  with  it,  a 
supply  of  oxygen  in  a  concentrated  state  is  presented  to  it, 
and  the  platinum,  without  losing  any  of  its  inherent  proper- 
ties, effects  chemical  combination,  the  alcohol  undergoing  slow 
combustion  and  being  converted  into  acetic  acid.  In  order 
that  the  reaction  may  continue  it  is,  of  course,  necessary  to 
present  fresh  oxygen  to  the  platinum  to  replace  that  which 
has  been  withdrawn.  The  two  actions  then  go  on  side  by 
side. 

This  can  be  illustrated  by  an  apparatus  similar  to  Fig.  1. 

It  consists  of  a  glass  bell  through 
the  mouth  of  which  a  long  funnel 
passes.  The  lower  end  of  this  funnel 
terminates  in  a  fine  point  so  that  the 
alcohol  may  percolate  very  slowly. 
The  vessel  is  placed  upon  supports 
within  a  dish  in  which  is  a  saucer 
or  small  shallow  basin  containing 
the  platinum  black.  The  interspace 
between  the  bottom  of  the  dish  and 
the  glass  bell  serves  for  the  circula- 
tion of  air  in  the  latter.  A  short, 
time  after  the  alcohol  has  been 
poured  into  the  funnel  an  odor  of 
acetic  acid,  arising  from  the  acetic 
acid  vapors  which  are  generated,  is 
perceived  at  the  mouth  of  the  bell. 

These  vapors  condense  on  the  walls  of  the  bell  and  trickle  to 
the  bottom,  where  they  collect  in  the  vessel  in  the  dish.  It  is 
of  advantage,  for  the  success  of  the  experiment,  to  have  the 
alcohol  heated  to  about  90°  F.  before  pouring  it  in.  By 
washing  and  igniting  the  platinum  used  for  the  oxidation  of 
the  alcohol,  it  can  be  again  employed  for  the  same  purpose. 


THEORY    OF    THE    FORMATION    OF    VINEGAR.  11 

Independent  of  the  purely  chemical  methods  which,  with 
the  exception  of  that  by  which  acetic  acid  is  produced  by  the 
destructive  distillation  of  wood,  are  of  no  practical  importance, 
the  formation  of  vinegar,  no  matter  what  method  may  be 
adopted,  can  only  be  effected  in  the  presence  of  certain  organ- 
isms. It  has  long  been  known  that  organisms  to  which  the 
term  mother  of  vinegar  has  been  applied,  develop  upon  liquids 
containing,  besides  alcohol,  certain  other  substances,  for 
Instance,  upon  weak  wine  or  beer,  and  this  mother  of  vinegar 
has  also  been  used  for  making  vinegar  on  a  large  scale.  To 
Pasteur,  however,  belongs  the  incontestable  merit  of  having 
more  accurately  examined  the  relations  of  these  organisms  to 
the  formation  of  vinegar.  These  examinations  gave  rise  to 
his  experiments  on  the  diseased  alteration  of  wine,  which  were 
later  on  superseded  by  his  researches  on  the  formation  of  wine 
vinegar. 

Pasteur  found  that  upon  the  surface  of  every  fluid  capable, 
by  reason  of  its  composition,  of  being  converted  into  vinegar, 
organisms  develop  immediately  after  the  commencement  of  the 
formation  of  vinegar.  He  recognized  these  organisms  as  fun- 
goid plants  of  a  low  order  and  called  them  Mycoderma  aceti. 
More  recent  researches  on  the  botanical  nature  of  these  plants 
show  them  to  belong  to  the  group  of  lowest  fungoid  organisms, 
to  which  the  term  bacteria  or  schizomycetes  has  been  applied. 

The  Bacterium  aceti,  the  name  applied  to  this  organism, 
consists  of  a  single,  generally  globular  or  filiform  cells,  its 
special  characteristic  being  its  mode  of  propagation,  which  is 
effected  by  the  division  of  the  cell  into  two,  and  then  a  separa- 
tion or  splitting  of  both. 

The  exceedingly  minute  size  of  the  schizomycetes  and  their 
great  resemblance  to  each  other  make  their  accurate  determina- 
tion very  difficult,  and  hence  it  is  customary  to  name  the  better 
known  species  in  accordance  with  the  chemical  products  they 
form  or  in  accordance  with  the  phenomena  they  produce. 
Among  the  first  kind  may  be  classed  those  which  effect  the 
formation  of  acetic,  lactic,  butyric  acids,  while  other  very  little 


12  MANUFACTURE    OF    VINEGAR. 

known  bacteria  must  be  considered  as  the  cause  of  the  so- 
called  nitric  acid  fermentation,  and  again  others  appear  in 
putrid  fermentation.  A  special  group  of  bacteria  reaches  de- 
velopment in  animal  organisms  and  gives  rise  to  terrible  dis- 
eases, some  causing  rinderpest,  others  tuberculosis  and  various 
other  maladies.  Cholera  and  other  epidemics  have  been  found 
to  be  due  to  certain  bacteria. 

The  bacteria  causing  disease  are  of  course  very  interesting 
to  the  physician,  but  to  the  manufacturer  of  vinegar  a  thorough 
knowledge  of  the  conditions  of  life  governing  the  vinegar 
bacteria  is  of  the  utmost  importance  in  order  to  conduct  the 
manufacture  in  such  a  manner  that  disturbances  shall  rarely 
occur,  and  should  they  happen,  that  he  may  be  able  to  remove 
them.  It  may  therefore  be  said  that  the  entire  art  of  the  man- 
ufacture of  vinegar  consists  in  an  accurate  knowledge  of  the 
conditions  of  life  of  the  vinegar  bacteria  and  in  the  induction 
of  these  conditions  of  life.  As  long  as  the  latter  are  main- 
tained the  process  of  the  formation  of  vinegar  will  go  on  with- 
out disturbance,  and  the  origination  of  new  generations  of 
vinegar  ferment  be  connected  with  the  conversion  of  certain 
quantities  of  alcohol  into  vinegar. 

Pasteur  regarded  the  bacterial  growth  mentioned  above  as 
consisting  of  a  single  species.  Hansen,  however,  showed  in 
1878,  that  in  the  spontaneous  souring  of  beer  at  least  two  dif- 
ferent species  of  bacteria  can  come  into  action,  one  of  which 
he  named  Mycpderma  aceti  and  the  other  Mycoderma  Pasteur- 
ianum.  At  the  suggestion  of  W.  Zopf,  he  afterwards  changed 
these  names  to  Bacterium  aceti  and  Bacterium  Pasteurianum  re- 
spectively. The  number  of  species  has  been  further  increased 
by  recent  investigations,  and  among  these  acetic  acid  bacteria 
there  are  several,  the  activity  of  which  is  distinctly  different, 
and  the  employment  of  a  pure  culture  of  systematical!^  selected 
species  would  be  desirable  in  the  manufacture  of  vinegar. 
Searching  investigations  into  the  chemical  activity  of  the  dif- 
ferent species  of  acetic  acid  bacteria  would  be  not  only  oppor- 
tune in  the  interests  of  science,  but  also  highly  important  in  the 
practice  of  the  vinegar  industry. 


VINEGAR    FERMENT    AND    ITS    CONDITIONS    OF    LIFE.  13 

CHAPTER  III. 

THE  VINEGAR  FERMENT  AND  ITS  CONDITIONS  OF  LIFE. 

A.  The  Vinegar  Ferment — While  but  little  is  known  about 
the  origin  of  the  vinegar  ferment,  experiments  have  shown 
these  organisms  to  be  everywhere  distributed  throughout  the 
air  and  to  multiply  at  an  enormous  rate  when  fluids  of  a  com- 
position suitable  for  their  nutriment  are  presented  to  them. 
A  fluid  especially  adapted  for  this  purpose  is,  for  instance, 
throughly  fermented  ripe  wine,  its  exposure  in  a  shallow  vessel 
at  the  ordinary  temperature  of  a  room  being  sufficient  to  in- 
duce the  propagation  of  the  vinegar  bacteria  reaching  it  from 
the  air. 

The  experiment  is,  however,  certain  of  success  only  when 
made  with  ripe  wine,  by  which  is  meant  wine  which  shows  but 
little  turbidity  when  vigorously  shaken  in  contact  with  air  and 
exposed  in  a  half-filled  bottle  to  the  air.  Young  wine  contains 
a  large  quantity  of  albuminous  substances  in  solution,  and- is 
especially  adapted  for  the  nutriment  of  an  organism,  the  sac- 
charomyces  mesembryanthemum  belonging  to  the  saccharomy- 
cetes.  It  develops  upon  the  surface  of  such  wine  as  a  thick 
white  skin,  which  later  on  becomes  wrinkled  and  prevents  the 
growth  of  the  vinegar  ferment.  A  fluid  well  adapted  for  the 
nutriment  of  the  vinegar  ferment  and  which  may  be  substituted 
for  wine  for  its  culture  is  obtained  by  adding  5  to  6  per  cent. 
of  alcohol  and  about  J  per  cent,  of  malt  extract  to  water. 

By  exposing  this  fluid,  or  ripe  wine  at  the  ordinary  tempera- 
ture of  a  room,  best  in  a  dish  covered  by  a  glass  plate  resting 
upon  small  wooden  blocks  to  prevent  the  access  of  dust,  the 
formation  of  a  thin  veil-like  coating  upon  the  surface  will  in  a 
few  days  be  observed.  The  wine  soon  exhibits  the  character- 
istic odor  and  taste  of  acetic  acid,  and  in  a  few  days  assumes  a 
somewhat  darker  color,  and  deposits  a  slight  brownish  sedi- 
ment consisting  of  decayed  vinegar  ferment.  In  14  to  21  days 


14  MANUFACTURE    OF    VINEGAR. 

the  fluid  is  entirely  converted  into  vinegar,  i.  e.,  it  contains  no 
more  alcohol,  but  in  place  of  it  the  corresponding  quantity  of 
acetic  acid. 

By  exposing  the  vinegar,  thus  obtained  for  a  longer  time  to 
the  air,  a  thick  white  skin  of  mold  may  happen  to  form  on  the 
surface,  and  on  testing  the  fluid,  it  will  be  found  that  the  con- 
tent of  acetic  acid  steadily  decreases,  the  mold  which  is  able  to 
convert  the  alcohol  into  water  and  carbonic  acid  possessing 
also  the  power  of  forming  the  same  products  from  acetic  acid. 

The  process  above  described  of  the  destruction  of  the  wine 

FIG.  2 


and  its  conversion  into  vinegar  by  a  veil-like  coating  of  vinegar 
ferment  occurs  most  frequently,  though  a  thick  spume,  the  so- 
called  mother  of  vinegar,  may  also  happen  upon  the  surface. 
This  phenomenon  will  be  referred  to  later  on. 

On  examining  under  the  microscope  a  drop  taken  from  the 
surface  of  the  wine  when  the  veil  of  vinegar  ferment  com- 
mences to  form,  a  picture  like  that  shown  in  Fig.  2  presents 
itself.  In  a  somewhat  more  advanced  stage,  formations  re- 
sembling chains  and  strings  of  beads  appear  more  frequently, 
and  when  finally  the  development  of  the  ferment  is  in  full 


VINEGAR    FERMENT    AND    ITS    CONDITIONS    OF    LIFE.  15 

progress,  it  appears  as  an  aggregation  of  numerous  single  cells 
mixed  with  double  cells  and  many  other  cells  strung  together 
like  beads.  The  field  of  vision  of  the  microscope  is  then  com- 
pletely filled  with  a  large  number  of  colorless  globules,  which 
are  present  either  singly  or  in  combinations  of  two,  formations 
resembling  chains  or  strings  of  beads  being  of  rare  occurrence. 
In  many  of  the  separately-occurring  formations  oval  forms,  gen- 
erally slightly  contracted  in  the  centre,  are  observed,  this  con- 
traction indicating  the  place  where  the  splitting  of  one  cell 
into  two  new  cells  takes  place.  By  vigorously  shaking  the 
fluid  before  viewing  it  under  the  microscope,  very  few  of  the 
above  mentioned  bead-like  formations  will  be  found,  but  more 
frequently  the  contracted  ones.  By  observing  for  hours  a  drop 
of  the  fluid  containing  the  ferment  in  an  advanced  state  of  de- 
velopment, the  globules  strung  together  will  be  noticed  to  fall 
apart  when  at  rest.  Hence  it  may  be  supposed  that  in  the 
propagation  of  cells  by  splitting,  the  newly  formed  cells  ad- 
here together  up  to  a  certain  stage,  and  later  on  separate  in  the 
fluid  when  in  a  quiescent  state.  Like  every  other  organism 
the  vinegar  ferment  only  lives  for  a  certain  time,  and  after 
dying  sinks  below  the  fluid  and  forms  upon  the  bottom  of  the 
vessel  the  above-mentioned  sediment.  The  latter  appears 
under  the  microscope  in  "the  same  form  as  the  living  ferment, 
but  differs  from  it  in  being  less  transparent,  and  of  a  brownish 
color.  The  propagation  of  the  vinegar  ferment  takes  place 
very  rapidly,  and  it  will  be  found  in  a  few  hours  after  the  com- 
mencement of  its  development  in  all  stages  of  life  upon  the  sur- 
face of  the  fluid,  it  being  possible  to  distinguish  cells  of  from 
1.5  to  3.5  micromillimeters.* 

The  vinegar  ferment  requiring  free  oxygen  for  its  propa- 
gation, grows  exuberantly  only  upon  the  surface  of  the  nutrient 
fluids.  By  filling  a  bottle  about  four  fifths  full  with  wine,  and 
after  allowing  the  vinegar  ferment  to  develop,  closing  the  mouth 
of  the  bottle  with  the  hand,  and  submerging  the  neck  of  the 

*  One  micromillimeter  =•  j^  millimeter. 


16  MANUFACTURE    OF    VINEGAR. 

bottle  in  water,  the  fluid  will  be  seen  to  rise  for  some  time  in 
the  bottle,  and  then  remain  stationary.  A  determination  of  the 
content  of  acetic  acid  immediately  before  the  commencement 
of  this  experiment,  and  a  few  days  after,  shows  but  a  slight  in- 
crease in  acetic  acid,  because  the  ferment  has  consumed  the 
free  oxygen  present  in  the  bottle,  the  essential  condition  for  its 
further  development  is  wanting,  and  it  must  cease  its.  activity, 
without,  however,  perishing.  It  may  here  be  remarked  that 
the  vinegar  ferment,  like  the  majority  of  bacteria,  possesses  an 
extraordinary  vitality.  Under  unfavorable  conditions  it  passes 
into  a  kind  of  quiescent  state,  during  which  no  perceptible  in- 
crease of  cells  takes  place,  and  it  may  remain  in  this  state  for 
a  long  time  without  suffering  destruction,  but  as  soon  as  the 
conditions  for  its  nutriment  are  again  presented,  propagation 
in  a  normal  manner  recommences. 

The  great  rapidity  of  propagation  of  the  vinegar  bacteria 
is  shown  by  an  experiment  of  some  importance  to  the  practice. 
Pour  into  a  shallow  vat,  about  three  feet  in  diameter,  a  fluid 
suitable  for  the  nutriment  of  the  bacteria,  and  divide  upon  the 
surface  by  means  of  a  thin  glass  rod  small  drops  of  wine,  upon 
which  the  frequently  mentioned  veil  has  been  formed.  In  a 
few  hours  the  entire  surface  of  the  fluid  in  the  vat  will  be 
covered  with  vinegar  bacteria,  spreading  concentrically  froni 
the  points  where  the  drops  of  wine  have  been  distributed. 
From  this  it  will  be  seen  that  the  culture  of  the  ferment  for 
the  purpose  of  manufacturing  vinegar  offers  no  difficulties, 
provided  all  conditions  for  its  propagation  be  observed. 

7?.  Conditions  for  the  Nutriment  of  the  Vinegar  Ferment.  The 
conditions  most  favorable  for  the  development  of  the  vinegar 
ferment,  and  for  converting  in  the  shortest  time  the  largest 
quantity  of  alcohol  into  acetic  acid,  have  been  determined  by 
many  observations  and  long  experience  in  the  practice.  These 
conditions  will  first  be  briefly  enumerated,  and  then  the  sep- 
arate points  more  fully  discussed. 

For  the  vinegar  bacteria  to  settle  upon  a  fluid,  and  for  their 
vigorous  propagation,  the  following  factors  are  required  : 


VINEGAR    FERMENT    AND    ITS    CONDITIONS    OF    LIFE.  17 

1.  A  fluid  which,  besides  alcohol  and  water,  contains  nitro- 

genous bodies  and  alkaline  salts.     The  quantities  of 
these  bodies  must,  however,  not  exceed  a  certain  limit. 

2.  The  fluid  must  be  in  immediate  contact  with  oxygen 

(atmospheric  air). 

3.  The  temperature  of  the  fluid  and  the  air  surrounding  it 

must  be  within  certain  limits. 

As  regards  the  composition  of  the  nutrient  fluid  itself,  it 
must  contain  all  the  substances  required  for  the  nutriment  of 
a  plant  of  a  low  order,  such  substances  being  carbohydrates, 
albuminates  and  salts.  Alcohol  must  be  named  as  a  specific 
nutriment  of  the  vinegar  ferment,  provided  the  supposition 
that  the  latter  consumes  the  alcohol  and  separates  in  its  place 
acetic  acid,  is  correct.  The  quantity  of  alcohol  in  the  fluid 
intended  for  making  vinegar  must,  however,  not  exceed  a 
certain  limit,  a  content  of  15  per  cent,  appearing  to  be  the 
maximum  at  which  acetic  fermentation  can  be  induced. 
But  even  a  content  of  12  to  13  per  cent,  of  alcohol  is  not  very 
favorable  for  the  vegetation  of  the  vinegar  ferment,  and  every 
manufacturer  knows  the  difficulty  of  preparing  vinegar  from 
such  a  fluid.  A  small  quantity  of  acetic  acid  in  the  nutrient 
medium  exerts  also  an  injurious  influence  upon  the  vinegar 
ferment.  Upon  a  fluid  containing  12  to  13  per  cent,  of  acetic 
acid  and  1  to  2  per  cent,  of  alcohol,  the  ferment  vegetates  only 
in  a  sluggish  manner,  and  considerable  time  is  required  to  con- 
vert this  small  quantity  of  alcohol  into  acetic  acid. 

That  the  vinegar  ferment  cannot  live  in  dilute  alcohol  alone 
may  be  shown  by  a  simple  experiment.  By  impregnating  a 
fluid  consisting  only  of  water  and  alcohol,  a  very  small  quan- 
tity of  acetic  acid  is  formed  to  be  sure,  but  the  ferment  perishes 
in  a  short  time — it  starves  to  death.  A  fluid  suitable  for  its 
nourishment  must,  therefore,  contain  the  above-mentioned 
nutrient  substances,  sugar,  dextrine,  or  similar  combinations 
occuring  in  wine,  malt  extract,  and  beer,  being  generally  em- 
ployed as  carbohydrates.  These  fluids  further  contain  nitro- 
genous combinations  which  may  serve  as  nutrient  for  the  fer- 
2 


18  MANUFACTURE    OF    VINEGAR. 

inent,  also  considerable  quantities  of  phosphates.  Hence,  by 
an  addition  of  wine,  malt  extract,  beer,  or  any  fruit  wine  (apple 
or  pear  cider)  to  a  mixture  of  alcohol  and  water,  a  fluid  can 
be  prepared  that  contains  all  the  substances  essential  to  the 
nutriment  of  the  ferment. 

The  necessary  quantity  of  these  nutrient  substances,  as  com- 
pared with  that  of  alcohol,  is  very  small,  since  the  quantity  by 
weight  of  vinegar  ferment  required  for  the  conversion  of  a  very 
large  amount  of  alcohol  into  vinegar  is  only  a  few  fractions  of 
one  per  cent,  of  the  weight  of  alcohol  used.  Hence  the  manu- 
facturer may  be  very  sparing  with  the  addition  of  nutrient 
substances  to  the  fluid  to  be  converted  into  vinegar,  without 
having  to  fear  that  the  ferment  will  be  stinted. 

The  vinegar  ferment  is  very  sensitive  to  sudden  changes 
in  the  composition  of  the  fluids  upon  which  it  lives,  and  suf- 
fers injury  by  such  changes  which  are  recognized  by  dimin- 
ished propagation  and  a  decrease  in  the  conversion  of  alcohol 
into  acetic  acid. 

By  transferring,  for  instance,  vinegar  ferment  which  had  nor- 
mally vegetated  upon  a  fluid  containing  only  4  to  5  per  cent, 
of  alcohol,  to  one  with  a  content  of  10  to  11  per  cent.,  its  pro- 
pagation, as  well  as  its  fermenting  energy,  decreases  rapidly 
and  remains  sluggish,  until  a  few  new  generations  of  cells  have 
been  formed  which  are  better  accustomed  to  the  changed  con- 
ditions. By  bringing,  on  the  other  hand,  a  ferment  from  a 
fluid  rich  in  alcohol  upon  one  containing  a  smaller  percentage, 
the  disturbances  in  the  conditions  of  the  ferment  can  also  be 
observed,  but  they  exert  a  less  injurious  influence  upon  the 
process  of  the  formation  of  vinegar  than  in  the  former  instance. 

The  process  of  nutriment  of  the  vinegar  ferment,  however, 
must  not  be  understood  to  consist  simply  in  the  consumption 
of  sugar,  albuminates  and  salts.  It  differs  according  to  the 
composition  of  the  nutrient  medium,  and  is  so  complicated  as 
to  require  very  thorough  study  for  its  explanation.  If,  for  in- 
stance, wine  is  converted  into  vinegar,  and  the  composition  of 
the  latter  compared  with  that  of  the  original  wine,  it  will  be 


VINEGAR    FERMENT    AND    ITS    CONDITIONS    OF    LIFE.  19 

found  that  not  only  the  alcohol  has  been  converted  into  acetic 
acid  and  the  fluid  has  suffered  a  small  diminution  of  extractive 
substances  and  salts,  which  might  be  set  down  to  the  account 
of  the  nutriment  of  the  ferment,  but  that  the  quantity  of  tar- 
taric,  malic  and  succinic  acids  has  also  decreased,  as  well  as 
that  of  glycerine,  and  of  the  latter  even  nothing  may  be  pres- 
ent. Hence  it  must  be  supposed  that  the  vinegar  ferment 
derives  nutriment  also  from  these  substances,  or  that  the  fer- 
menting activity  acts  upon  them  as  well  as  upon  the  alcohol. 
There  is  finally  the  fact  of  great  importance  for  the  practice, 
but  which  has  not  yet  been  sufficiently  explained,  that  the 
vinegar  ferment  develops  more  rapidly  upon  a  fluid  which, 
besides  the  req-uisite  nutrient  substances,  contains  a  certain 
quantity  of  acetic  acid,  than  upon  a  fluid  entirely  destitute  of 
it.  Regarding  the  supply  of  air,  it  may  be  said  that,  while 
for  mere  existence  the  vinegar  ferment  requires  comparatively 
little  air,  large  quantities  of  it  are  necessary  for  its  vigorous 
propagation  and  fermenting  activity.  In  the  practice  it  is 
aimed  to  accomplish  this  by  exposing  the  fluid  in  which  the 
ferment  lives  in  thin  layers  to  the  action  of  the  air,  and,  in 
fact,  upon  this  the  entire  process  of  the  quick  method  of  man- 
ufacture is  based. 

Besides  the  above-mentioned  factors,  the  temperature  to 
which  the  ferment  is  exposed  is  of  great  importance  as  regards 
its  development.  The  limits  at  which  the  propagation  of  the 
ferment  and  its  vinegar-forming  activity  are  greatest,  lie  be- 
tween 68°  and  95°  F.  Above  this  limit  the  formation  of 
vinegar  decreases  rapidly,  and  ceases  entirely  at  104°  F. 
However,  when  the  temperature  is  again  reduced  to  86°  F., 
the  ferment  reassumes  its  activity.  At  a  temperature  exceed- 
ing 104°  F.  the  ferment  suffers  perceptible  injury  ;  heated  to 
103°  F.  it  becomes  sensibly  weaker,  and  at  first  propagates 
very  slowly,  regaining  its  original  vigorous  development  only 
after  several  generations.  When  the  temperature  of  the  fluid 
is  raised  to  122°  F.  the  ferment  perishes. 

The  ferment  appears  to  be  less  affected  by  low  temperatures. 


20  MANUFACTURE    OF    VINEGAR. 

If  the  temperature  of  a  fluid  which  shows  an  exuberant  vege- 
tation of  ferment  is  reduced  to  50°  F.,  the  formation  of  vinegar 
continues,  though  at  a  much  reduced  rate.  Special  experi- 
ments have  shown  that  when  wine  with  a  vegetation  of  fer- 
ment is  converted  into  ice  by  being  exposed  to  a  temperature 
of  14°  F.,  and  then  melted  and  heated  to  59°  F.,  the  ferment 
recommences  to  grow  and  to  form  acetic  acid.  It  must,  how- 
ever, be  remarked  that  while  vinegar  ferment  in  a  state  of 
development  keeps  up  a  slow  vegetation  when  the  fluid  is  re- 
duced to  a  low  temperature,  it  is  extremely  difficult  to  culti- 
vate it  upon  a  cold  fluid.  This  is  very  likely  the  reason  why 
acetic  degeneration  is  not  known  in  cold  wine  cellars,  while 
in  cellars  with  a  temperature  of  over  59°  F.,  this  dreaded  pro- 
cess can  only  be  guarded  against  by  the  greatest  care. 

Since  the  propagation  of  the  ferment  and  its  fermenting 
activity  increase  with  a  higher  temperature,  it  would  appear 
most  suitable  to  keep  the  temperature  of  the  fluid  to  be  con- 
verted into  vinegar  as  near  the  uppermost  limit  of  95°  F.  as 
possible.  Experience,  however,  has  shown  that  at  this  temper- 
ature disturbances  are  of  frequent  occurrence  in  -the  genera- 
tors, and  for  this  reason  one  of  86°  to  89°  F.  is  generally 
preferred.  The  process  of  the  formation  of  vinegar  itself  ex- 
plains why  disturbances  may  easily  occur  at  a  high  tempera- 
ture. It  is  a  chemical  (oxidizing)  process  in  which  a  certain 
quantity  of  heat,  depending  on  the  quantity  of  alcohol  to  be 
oxidized  within  a  certain  time,  is  always  liberated.  If  now 
by  the  use  of  a  temperature  close  to  95°  F.,  the  activity  of  the 
ferment  is  strained  to  the  utmost,  a  large  quantity  of  alcohol 
is  in  a  short  time  converted  into  acetic  acid,  and  consequently 
so  much  heat  is  liberated  that  the  temperature  in  the  gener- 
ator rises  above  the  permissible  maximum  and  the  ferment 
immediately  ceases  its  activity.  Thus  it  may  happen  that  in 
a  generator  which  has  satisfactorily  worked  for  some  time, 
tne  formation  of  vinegar  ceases  all  at  once,  and  on  examining 
the  thermometer  placed  on  the  apparatus  the  cause  will  be 
generally  found  to  be  due  to  too  high  a  temperature. 


VINEGAR    FE11MENT    AND    ITS    CONDITIONS    OF    LIFE.  21 

Mother  of  Vinegar — In  connection  with  the  description  of 
the  conditions  of  life  of  the  vinegar  bacteria,  a  peculiar  form- 
ation, playing  in  many  cases  a  role  in  the  practice  of  making 
vinegar,  has  to  be  mentioned.  This  is  the  so-called  mother  of 
vinegar,  the  term  having  very  likely  been  applied  to  it  on  ac- 
count of  its  causing  acetification  when  brought  into  a  fluid 
suitable  for  the  formation  of  acetic  acid.  The  first  botanical 
investigation  of  this  substance  was  made  in  1822  by  Persoon, 
who  described  the  organized  skin  developing  on  various  fluids, 
and  gave  it  the  general  name  of  Mycoderma,  i.  e.,  mucinous 
skin  or  fungoid  skin. 

Kiitzing,  in  1837,  showed  that  the  "  mother  of  vinegar"  is 
constructed  of  a  number  of  minute  dot-like  organisms — which 
are  now  called  bacteria — arranged  together  in  the  form  of 
chains.  These  he  classified  as  algae,  and  named  them  Ulvina 
aceti,  and  asserted  quite  positively  that  alcohol  is  converted 
into  acetic  acid  by  the  vital  activity  of  these  organisms. 
Kiitzing's  results,  however,  attracted  but  little  attention  because 
two  years  after  their  publication,  Liebig  appeared  on  the  scene 
with  his  theory  of  acetic  fermentation,  which  has  already  been 
referred  to,  in  which  no  mention  was  made  of  the  potency  of 
living  organisms,  but  the  "  mother  of  vinegar  "  was  asserted  to 
be  a  formation  devoid  of  life,  a  structureless  precipitate  of 
albuminous  matter.  One  of  the  reasons  put  forward  in  sup- 
port of  this  view  was  a  chemical  analysis  of  the  "  mother  of 
vinegar"  by  the  Dutch  chemist,  G.  Mulder,  who  because  he 
failed  to  discover  the  presence  of  any  ash  constituents,  thought 
that  it  must  be  regarded  as  a  compound  of  protein  and  cellu- 
lose. Mulder's  statement  was  refuted  in  1852  by  R.  Thomson, 
who  showed  that  a. sample  of  "  mother  of  vinegar"  contained 
94.33  per  cent,  water,  5.134  per  cent,  organic  matter  and  0.336 
per  cent.  ash. 

The  formation  of  mother  of  vinegar  can  always  be  success- 
fully attained  by  exposing  young  wine  to  the  air  until  the 
commencement  of  the  formation  of  mold  is  indicated  by  the 
appearance  of  white  dots  and  then  transferring  the  wine  to  a 


22  MANUFACTURE    OP    VINEGAR. 

room  having  a  temperature  of  86°  F.  At  this  temperature  the 
development  of  the  vinegar  ferment  proceeds  so  vigorously 
that  it  suppresses  the  mold  ferment,  and  the  peculiar  mass  con- 
stituting the  mother  of  vinegar  soon  forms  upon  the  surface. 

Mother  of  vinegar  occurs  so  generally  in  young  wine  which 
is  largely  used  for  the  preparation  of  wine  vinegar,  that  its 
formation  was  considered  as  inseparably  connected  with  that  of 
acetic  acid  from  alcohol,  while  actually  it  is  only  due  to  the 
peculiar  constitution  of  the  fluid  to  be  converted  into  vinegar. 
In  many  places  this  opinion  is  still  entertained,  and  especially 
where,  as  is  generally  the  case,  the  manufacture  of  vinegar 
from  wine  is  yet  carried  on  in  the  primitive  way  of  centuries 
ago.  In  speaking  of  the  preparation  of  vinegar  from  wine,  it 
will  be  shown  that  the  conversion  can  be  effected  by  means  of 
the  ordinary  vinegar  ferment  without  the  appearance  of  mother 
of  vinegar. 

Summary. 

Briefly  stated,  the  points  of  the  theoretical  conditions  of  the 
formation  of  vinegar  of  importance  to  the  manufacturer  are : — 

1.  Acetic  acid  is  formed  during  many  chemical  conversions. 

However,  for  the  manufacture  of  acetic  acid,  and  con- 
sequently of  vinegar  on  a  large  scale,  only  two  methods 
are  available,  viz.,  the  preparation  of  vinegar  from  al- 
cohol by  fermentation,  or  the  production  of  acetic  acid 
by  the  destructive  distillation  of  wood. 

2.  All   alcoholic  fluids  formed   by  vinous  fermentation  of 

sacchariferous  plant  juices  or  fermented  malt  extracts 
are  suitable  for  the  preparation  of  vinegar  by  fermenta- 
tion. Specially  prepared  mixtures  of  water,  alcohol 
and  vinegar  may  also  be  used  for  the  purpose,  provided 
they  contain  small  quantites  of  certain  organic  sub- 
stances and  salts,. and  not  over  14  per  cent  of  alcohol. 

3.  Acetic  fermentation  is  induced  by  a  microscopic  organ- 

ism belonging  to  the  bacteria,  and  the  conversion  of  the 
alcohol  into  acetic  acid  is  in  a  certain  ratio  to  the  pro- 
pagation of  this  organism. 


PRODUCTS    OF    ACETIC    FERMENTATION.  23 

4.  Besides  the  substances  mentioned  in  2,  the  vinegar  fer- 

ment requires  for  its  vigorous  development  free  oxygen 
and  a  temperature  lying  between  68°  and  95°  F. 

5.  In  the  acetic  fermentation  the  greater  portion  of  the  al- 

cohol is  converted  into  acetic  acid  and  water ;  besides 
these,  small  quantities  of  other  products  are  formed 
which  are  in  a  measure  not  yet  thoroughly  known.  In 
the  conversion  of  wine,  beer,  etc.,  other  combinations 
contained  in  the  fluids,  besides  alcohol,  are  also  essen- 
tially changed. 


CHAPTER  IV. 

PRODUCTS  OF  ACETIC  FERMENTATION. 

THE  formation  of  vinegar  by  fermentation  being  a  chemico- 
physiological  process,  many  and  complicated  chemical  pro- 
cesses must  take  place  in  the  fluid  to  be  converted  into  vine- 
gar in  order  to  produce  all  the  combinations  required  for  the 
propagation  of  the  ferment.  Attention  cannot  be  too  fre- 
quently called  to  the  fact  that  from  the  standpoint  of  the  manu- 
facturer, the  regular  propagation  of  the  ferment  is  the  main 
point  of  the  entire  manufacture,  the  quick  conversion  of  the 
alcohol  contained  in  the  fluid  being  a  necessary  consequence 
of  it. 

The  body  of  the  ferment,  however,  contains  cellulose,  albu- 
minous substances,  very  likely  fat  and  other  combinations  not 
yet  known,  all  of  which  must  be  formed  from  the  nutrient 
substances  (sugar,  dextrine,  albuminous  substances,  etc.), 
present.  It  being  very  probable  that  a  portion  of  the  alcohol 
contained  in  the  fluid  is  consumed  for  this  purpose,  a  small 
but  nevertheless  perceptible  loss  of  alcohol  will  occur  in  the 
production.  It  would  be  erroneous  to  suppose  that  the  con- 
version of  alcohol  into  acetic  acid  and  water  is  effected  accord- 


24  MANUFACTURE    OF    VINEGAR. 

ing  to  the  formula  given  on  p.  6,  since  a  certain  portion  of  it 
is  always  converted  into  other  combinations,  the  nature  and 
formation  of  which  can  only  be,  to  a  certain  extent,  explained. 

In  the  vinous  fermentation,  which  of  all  fermenting  pro- 
cesses has  been  most  thoroughly  studied,  it  is  found  that  from 
the  sugar,  besides  alcohol  and  carbonic  acid,  large  quantities 
of  glycerine  and  succinic  acid  and  probably  other  bodies  ,are 
formed,  which  must  undoubtedly  be  classed  among  the  pro- 
ducts of  vinous  fermentation.  Similar  processes,  no  doubt, 
take  place  in  acetic  fermentation,  and  besides  acetic  acid  and 
water  other  little-known  products  of  fermentation  are  regularly 
formed. 

According  to  the  nature  of  the  sacchariferous  fluids  sub- 
jected to  vinous  fermentation,  small  quantities  of  certain 
bodies  called  fusel  oils  are  formed  which  are  decidedly  pro- 
ducts of  fermentation.  They  impart  to  the  fermented  fluid, 
as  well  as  to  the  alcohol  distilled  from  it,  such  characteristic 
properties  that  from  the  odor  of  the  alcohol  a  correct  judg- 
ment can  be  formed  as  to  the  material  employed  in  its  prepa- 
ration. 

In  the  conversion  of  such  a  fluid,  or  of  alcohol  prepared 
from  it,  into  vinegar,  the  fusel  oils  are  also  changed — very 
likely  oxydized — and  with  some  experience  the  material  (wine, 
beer,  malt,  etc.),  from  which  the  vinegar  has  been  made  can 
be  determined  by  the  sense  of  smell.  The  quantities  of  aro- 
matic substances  which  reach  the  vinegar  in  this  manner  are, 
of  course,  very  small,  but  they  must  nevertheless  be  classed 
among  the  most  important  products  of  acetic  fermentation, 
they  being  characteristic  as  regards  the  derivation  of  the  vine- 
gar. Of  the  products  of  acetic  fermentation,  besides  acetic 
acid,  aldehyde  and  acetal  are  best  known,  these  combinations 
appearing  always,  even  in  small  quantities,  in  making  vinegar 
according  to  the  methods  customary  at  the  present  time. 

Acetic  Aldehyde  or  Acetaldeliyde,  commonly  called  simply 
aldehyde  (from  alcohol  dehydrogenatum),  is  obtained  by  oxidiz- 
ing spirits  of  wine  by  means  of  manganese  dioxide  (pyrolu- 


PRODUCTS    OF    ACETIC    FERMENTATION.  25 

site)  and  sulphuric  acid,  or  platinum  black,  in  the  presence 
of  air,  or  if  alcohol  or  ether  be  burning  without  a  sufficient 
supply  of  air.  It  is  also  formed  by  heating  a  mixture  of  cal- 
cium acetate  and  calcium  formate.  It  is  contained  in  con- 
siderable quantities  in  the  first  runnings  obtained  in  the 
manufacture  of  spirit  of  wine. 

To  prepare  pure  aldehyde,  3  parts  of  potassium  dichromate 
in  small  pieces  are  placed  in  a  flask  surrounded  by  a  freezing 
mixture  and  a  well-cooled  mixture  of  2  parts  of  spirit  of 
wine,  4  of  sulphuric  acid,  and  4  of  water  added.  After  con- 
necting the  flask  with  a  condenser  the  freezing  mixture  is  re- 
moved ;  a  violent  reaction  soon  sets  in,  and  the  liquid  begins 
to  boil.  The  vapors  have  first  to  pass  through  an  ascending 
tube  surrounded  by  warm  water  at  about  122°  F.  Alcohol 
and  various  other  products  are  condensed  and  flow  back,  while 
the  vapor  of  the  aldeh}Tde,  after  having  passed  through  a  de- 
scending condenser,  is  absorbed  in  anhydrous  ether. 

Pure  aldehyde  thus  obtained  is  a  colorless  liquid  of  the 
composition  C2H40.  Its  specific  gravity  is  0.800,  and  it  boils 
at  about  71.5°  F.  It  has  a  pungent  and  suffocating  odor, 
and  is  readily  soluble  in  water,  alcohol  and  acetic  acid.  Like 
all  the  aldehydes  it  is  very  easily  oxidized  and  acts,  therefore, 
as  a  powerful  reducing  agent.  Thus,  on  heating  it  with  a 
little  ammonia  and  nitrate  of  silver,  metallic  silver  separates 
outj  coating  the  sides  of  the  vessel  with  a  bright  mirror.  It 
combines  with  ammonia,  and  forms  a  crystalline  compound 
which  has  the  peculiar  odor  of  mice. 

Though  it  is  likely  that  in  the  manufacture  of  vinegar  by  the 
quick  process,  besides  aldehyde,  acetic  and  formic  ethers  are 
formed,  they  are  of  comparatively  little  importance  for  our 
purposes.  Of  more  importance,  however,  is  acetal,  the  forma- 
tion of  this  combination  affording  an  interesting  insight  into 
acetic  acid. 

Acetal  is  best  prepared  by  distributing  pieces  of  pumice, 
previously  moistened  with  25  per  cent,  alcohol,  over  a  large, 
glass  plate,  placing  watch  crystals  containing  platinum  black 


126  MANUFACTURE    OF    VINEGAR. 

upon  the  pieces  of  pumice,  and  covering  the  whole  with  a  large 
bell-glass.  The  alcohol  absorbed  by  the  pumice  being  con- 
verted into  acetic  acid,  60  percent,  alcohol  is  poured  upon  the 
plate  and  the  air  in  the  bell-glass  from  time  to  time  renewed. 
In  a  few  weeks  quite  a  thick  fluid  of  an  agreeable  odor  has 
collected  upon  the  glass  plate.  This  is  collected  and  dis- 
tilled, the  portion  passing  over  at  219°  F.  being  collected  by 
itself. 

Pure  acetal  is  composed  of  C6H1402.  It  is  a  colorless 
liquid,  has  a  specific  gravity  of  0.821,  and  boils  at  219.2°  F. 
It  has  a  refreshing  odor,  calling  to  mind  that  of  fruit  ethers. 
By  oxidizing  agents  it  is  rapidly  converted  into  acetic  acid. 
Nitrate  of  silver  in  the  presence  of  ammonia,  however,  is  not 
reduced  by  it,  and  it  remains  unchanged  on  boiling  with 
potash  lye.  From  its  composition  acetal  may  be  considered 
from  several  points  of  view.  It  may  be  regarded  as  an  ethyl 
alcohol  (glycol)  C2H602,  in  which  two  atoms  of  hydrogen 
have  been  replaced  by  two  molecules  of  the  radical  ethyl 
C2H5,  hence  thus 


__ 
"  C6HUO2  acetal. 

This  view  of  the  composition  of  acetal  is  supported  by  the 
fact  that  methyl  or  amyl  can  be  substituted  for  either  one  or 
both  molecules  of  ethyl  in  the  combination. 

According  to  other  opinions,  acetal  may  be  considered  as  a 
combination  of  aldehyde  and  aldehyde  ether  :  — 

C2H,O     aldehyde 
C4H100   aldehyde  ether 
C6H^62  acetal, 

or  as  a  combination  of  aldehyde  with  ethyl  alcohol,  one  mole- 
cule of  water  in  the  latter  having  been  replaced  by  the  alde- 
hyde :  — 


PRODUCTS    OF    ACETIC    FERMENTATION.  27 

Ethyl  alcohol:  2(C2H60— H20=C4H10O 
aldehyde  C2H4O 
acetal  C4HM02 

By  keeping  in  view  the  fact  that  the  process  of  the  formation 
of  vinegar  is  an  oxidation  of  the  alcohol  which  does  not  pro- 
ceed with  equal  energy  in  all  parts  of  the  apparatus,  it  will  be 
understood  that  during  this  process  aldehyde,  acetal,  and  acetic 
ether  may  be  formed  which,  if  the  operation  be  correctly  con- 
ducted, will  be  finally  converted  into  acetic  acid,  though  small 
quantities  of  them  will  be  found  in  the  vinegar  when  just  fin- 
ished and  exert  an  influence  upon  its  constitution. 

Pure  acetic  acid,  C2H402,  cannot  be  directly  obtained  from 
vinegar,  but  only  from  acetates  by  methods  which  will  be  de- 
scribed later  on.  The  strongest  acetic  acid  which  can  be  pre- 
pared is  known  as  glacial  acetic  acid,  from  its  crystallizing  in 
icy  leaflets  at  about  40°  F.  Above  about  60°  F.  the  crystals 
fuse  to  a  thin,  colorless  liquid  of  an  exceedingly  pungent  and 
well-known  odor.  Pure  acetic  acid  is  a  powerful  restorative 
when  applied  to  the  nostrils  in  impending  fainting.  It  is  the 
strongest  of  organic  acids  and  nearly  as  corrosive  as  sulphuric 
acid.  Applied  to  the  human  skin  it  acts  as  an  irritant,  causing 
redness  and  swelling,  followed  by  paleness  of  the  part,  and,  if 
its  application  be  prolonged,  it  is  followed  by  vesication  and 
desquamation  of  the  cuticle.  It  first  whitens  mucous  mem- 
branes, then  turns  them  brown,  causing  meanwhile  a  severe 
burning  pain.  Highly  concentrated  acetic  acid  is  a  solvent  of 
many  volatile  oils  and  resins,  and  in  practice  its  high  con- 
centration is  tested  by  its  ability  to  dissolve  lemon  oil,  since  in 
the  presence  of  only  2  per  cent,  of  water  in  the  acid,  lemon  oil 
is  no  longer  dissolved  by  it. 

The  specific  gravity  of  pure  acetic  acid  is  at  59°  F.: — 

According  to  Oudemans     .......  1.0553 

Roscoe 1.0564 

"  Kopp 1.0590 

Mendelejeff 1.0607 

"  Mohr    .  .  1.0600 


28  MANUFACTURE    OF    VINEGAR. 

According  to  Mohr's  determinations,  the  specific  gravity  of 
pure  acetic  acid  varies  much  at  different  temperatures,  it  being 

1.0630  at             54.5°  F. 

1.0600  "             59.0  " 

1.0555  u              68.0    " 

1.0198  77.0  " 

1.0480  79.0  ki 

Mixtures  of  acetic  acid  and  water  show  a  peculiar  behavior 
in  regard  to  their  specific  gravity,  the  latter  rising  steadily 
until  the  content  of  water  amounts  to  from  20  to  23  per  cent. 
The  density  of  the  liquid  then  diminishes  so  that  a  mixture 
containing  46  per  cent,  of  water  shows  the  same  specific 
gravity  as  the  anhydrous  acid.  From  this  point  on,  the 
specific  gravities  of  the  mixtures  decrease  with  the  increase  in 
the  content  of  water. 

This  peculiar  behavior  of  the  mixtures  renders  the  accurate 
determination  of  the  content  of  acid  in  a  concentrated  mix- 
ture, by  means  of  the  aerometer,  impossible.  There  are  a 
number  of  determinations  of  specific  gravities  of  acetic  acid 
with  varying  contents  of  water  (by  Mohr,  von  der  Toorn, 
Oudemans,  etc.),  but  they  differ  considerably  from  each  other, 
like  the  tables  at  the  end  of  this  volume,  so  that,  while  the 
specific  gravity  test  answers  very  well  for  the  determination 
of  the  amount  of  anhydrous  acid  in  dilute  solutions,  it  is  very 
fallacious  when  the  acid  increases  in  strength,  and  an  accurate 
determination  can  only  be  effected  by  chemical  methods. 

Highly  concentrated  acetic  acid  has  found  considerable  ap- 
plication in  photography  and  surgery,  and  frequently  occurs 
in  commerce  in  the  form  of  so-called  vinegar  essence.  The  acetic 
acid  occurring  under  this  name  is  generally  prepared  from 
wood  vinegar,  and  is  only  fit  for  the  preparation  of  table 
vinegar  when  a  chemical  examination  shows  no  trace  of  tar 
products,  which,  besides  acetic  acid,  are  formed  in  abundance 
in  the  destructive  distillation  of  wood. 

In  regard  to  the  composition  of  acetic  acid,  it  may  be  men- 
tioned that  one  atom  of  hydrogen  can  be  readily  replaced  by 


PRODUCTS    OF    ACETIC    FERMENTATION.  29 

univalent  metals  or  univalent  compound  radicals  which  may 
be  expressed  by 

H          '\0 

C2H30    JC 

TT    -| 

whereby  the  acetic  acid  is  considered  as  water  ^r  V  0  in  which 

one  atom  of  hydrogen  is  replaced  by  the  compound   radical 
C2H30  =  acetyl. 

If  the  one  atom  of  hydrogen  standing  by  itself  be  replaced 
by  a  univalent  metal,  a  neutral  acetate  is  formed,  for  instance  : 

Na 
C2H30 

or  sodium  acetate. 

If  this  atom  of  hydrogen  is  replaced  by  a  univalent  com- 
pound radical,  for  instance,  by  methyl  CH3,  or  ethyl  C2H5, 
the  so-called  compound  ethers  are  formed. 

CH3 
C2H30 

Acetic  acid— methyl  ether.  Acetic  acid— ethyl  ether. 

If  a  bivalent  metal  or  compound  radical  yields  a  neutral 
combination  with  acetic  acid,  the  substituted  hydrogen  in  two 
molecules  of  acetic  acid  must  evidently  be  replaced  by  this 
bivalent  metal,  for  instance  : — 

Ca  \Q 

2(C2H80)  j  u* 

Neutral  calcium  acetate. 

Theoretical  Yields  of  Acetic  Acid — In  industries  based  upon 
chemical  processes  a  distinction  is  made  between  the  theoreti- 
cal and  practical  yields. 

By  theoretical  yield  is  understood  the  quantity  of  the  body 
to  be  manufactured  which  would  result  if  no  losses  of  substance 
were  connected  with  the  chemical  process;  the  practical  yield, 
on  the  other  hand,  is  that  in  which  such  losses  are  taken 
into  account^  the  average  being  ascertained  by  long-continued 


30  MANUFACTURE    OF    VINEGAR. 

comparison  of  daily  yields.  The  closer  the  practical  yield  ap- 
proaches the  theoretical  one,  the  more  suitable  the  method 
pursued  in  the  production  evidently  is,  and  thus  the  manu- 
facturer, who  has  a  clear  idea  of  the  theoretical  yield,  can 
readily  judge  of  the  value  of  his  method  by  comparing  it 
with  the  practical  yield  attained. 

Now  suppose  no  loss  of  substance  (by  evaporation  or  forma- 
tion of  other  combinations)  occurs  in  the  conversion  of  alcohol 
into  acetic  acid,  it  can  be  readily  calculated  from  the  composi- 
tion of  the  two  bodies  how  many  parts  by  weight  of  acetic  acid 
can  be  formed  from  a  determined  number  of  parts  by  weight 
of  alcohol. 

Alcohol  has  the  composition  C2H60,  or  an  atomic  weight 
of  46,  because  : — 

C2  =  .  .  .24 
H6=  6 

0  =      .         .         .16 

Make  .         .46 

The  composition  of  acetic  acid  is  C2H402  and  its  molecular 
weight  60,  because : 

C2  =  .  '  .  .24 
H4=  .  .  .  4 
02  =  .  .  .32 

Make  .         .      60 

Hence  from  46  parts  by  weight  of  alcohol  60  parts  by 
weight  of  acetic  acid  may  be  formed,  or  by  taking  100 
parts  of  alcohol  it  follows  that  100  parts  by  weight  of  alcohol 
must  yield  130.43478  parts  by  weight  of  acetic  acid.  This  in- 
crease in  weight  has  to  be  attributed  to  the  absorption  of  one 
atom  of  oxygen,  atomic  weight  16,  against  the  loss  of  two 
atoms  of  hydrogen,  atomic  weight  2.  Since  these  two  atoms 
of  hydrogen  are  themselves  oxidized  to  water  by  the  absorp- 


PRODUCTS    OF    ACETIC    FERMENTATION.  31 

tion  of  oxygen,  the  total  yield  from  100  parts  by  weight  of 
alcohol  would  be  : 

Acetic  acid  .         .         .     130.43478  parts  by  weight. 
Water  39.13043       "       " 


Total.         .     169.56521  parts  by  weight. 

The  quantity  of  oxygen  required  to  form  acetic  acid  and 
water  from  46  parts  by  weight  of  alcohol,  amounts  to  32  parts 
by  weight,  hence  for  100  parts  to  69.562  parts  by  weight.  The 
oxygen  is  conducted  to  the  alcohol  in  the  form  of  air,  and  it 
can  be  readily  calculated  how  much  of  the  latter  is  required  to 
convert  a  given  quantity  of  alcohol,  for  instance  ,100  grammes, 
into  acetic  acid.  In  round  numbers  the  air  contains  in  100 
parts  by  weight  23  parts  by  weight  of  oxygen.  Since  1  liter 
of  air  of  68°  F.,  i.  e.,  of  that  temperature  which  should  at  the 
least  always  prevail  in  the  vinegar  generators,  weighs  1.283 
grammes,  the  oxygen  contained  in  it  weighs  0.29509  grammes. 
Since,  as  above  stated,  69.562  parts  by  weight  are  necessary 
for  the  conversion  of  100  parts  by  weight  of  alcohol  into  acetic 
acid,  it  follows  that  235.70  liters  of  air  are  required  for  the 
same  purpose. 

Examinations  as  to  the  content  of  oxygen  in  the  air  escap- 
ing from  well-conducted  vinegar  generators  have  shown  that 
on  an  average  only  one-quarter  of  the  entire  content  of  oxygen 
is  consumed  in  the  formation  of  vinegar,  hence  four  times  the 
theoretically  calculated  quantity  of  air  must  pass  through  the 
apparatus  to  completely  convert  the  alcohol  into  acetic  acid. 
Hence  100  grammes  of  alcohol  require  at  least  942.92  liters  of 
air  for  their  conversion  into  acetic  acid,  and,  without  being  far 
wrong,  it  may  be  assumed  that  in  a  vinegar  factory,  in  round 
numbers,  1000  liters,  or  one  cubic  metre  of  air,  are  required 
for  every  100  grammes  of  alcohol  to  be  converted  into  acetic 
acid. 

A  vinegar  generator,  on  an  average,  converts  daily  3  litres 
of  alcohol  into  acetic  acid  ;  3  litres  of  absolute  alcohol  (specific 


32  MANUFACTURE    OF    VINEGAR. 

gravity  0.794)  weigh  2382  grammes.  Now,  if,  as  stated  above, 
1  cubic  metre  of  air  is  required  for  every  100  grammes  of 
alcohol,  it  follows  that  23.82  cubic  metres,  or  23,820  liters  of 
air  must  pass  daily  through  each  vinegar  generator  in  opera- 
tion. * 

Calculated  to  16  working  hours  a  day,  somewhat  more  than 
0.4  liter  (more  accurately  0.413  liter)  must  pass  every 
second  through  the  generator  in  order  to  supply  the  quantity 
of  oxygen  required  for  the  conversion  of  alcohol  into  acetic 
acid. 

Since  the  formation  of  vinegar  has  theoretically  to  be  con- 
sidered as  a  process  of  combustion,  in  which  of  4G  parts  by 
weight  of  alcohol,  2  parts  by  weight  of  hydrogen,  or  of  100 
parts  by  weight  of  alcohol  4.34782  parts  by  weight  of  hydro- 
gen, are  consumed,  the  quantity  of  heat  liberated  by  the  con- 
version of  100  parts  by  weight  of  alcohol  into  acetic  acid  can 
also  be  calculated.  By  combustion,  1  gramme  of  hydrogen 
yields  34.126  units  of  heat,  and  hence  4.34782  grammes  of 
hydrogen,  148.373  units  of  heat,  i.  e.,  in  the  conversion  of  100 
grammes  of  alcohol  into  acetic  acid  sufficient  heat  is  liberated 
to  heat  148.373  kilogrammes  of  water  from  0°  C.  to  1°  C.,  or 
1.48  kilogrammes  from  0°  C.  to  boiling,  and  thus  a  consider- 
able development  of  heat  is  caused  by  the  rise  of  temperature 
in  the  apparatus,  in  which  a  vigorous  formation  of  vinegar 
takes  place. 

In  answer  to  the  question,  what  can  the  practical  manufac- 
turer of  vinegar  learn  from  these  theoretical  explanations,  it 
may  be  said  there  are  many  points  of  great  importance  for  the 
execution  of  the  work.  The  calculation  of  air  shows  that  the 
alcohol  requires  a  large  supply  ;  but  the  generators  in  general 
use  in  the  quick  process  are  by  no  means  so  arranged  as  to  be 
adequate  to  the  theoretical  demands.  In  fact  it  may  be  said 
that  most  of  them  allow  only  a  limited  change  of  air  and  con- 

*  It  is  always  supposed  that  the  manufacture  of  vinegar  is  effected  in  generators 
used  in  the  quick  process. 


PRODUCTS    OF    ACETIC    FERMENTATION.  33 

sequently  work  slower  than  they  actually  should.  That  the 
generators  now  in  use  are  deficient  is  conclusively  proved  by 
the  numerous  constructions  which  have  been  proposed,  especi- 
ally in  modern  times,  whose  chief  aim  is  to  afford  a  free  pas- 
sage to  the  air. 

The  fact  that  considerable  heat  is  developed  in  the  interior 
of  the  generator  deserves  consideration  in  connection  with  the 
heating  of  the  manufactory.  If  the  temperature  in  the  latter 
is  so  high  as  nearly  to  approach  the  acme,  i.  e.,  the  temperature 
most  favorable  for  the  formation  of  vinegar,  it  may  easily 
happen  that,  in  consequence  of  the  vigorous  oxidation  of  the 
alcohol,  the  temperature  in  the  interior  of  the  generators  be 
increased  to  such  an  extent  as  to  exceed  this  acme,  and  the 
activity  of  the  vinegar  ferment  would  immediately  diminish 
and  even  cease  altogether. 

If,  on  the  other  hand,  the  temperature  of  the  workroom  is 
kept  too  low,  the  generators  act  sluggishly  and  do  not  produce 
so  much  as  when  the  correct  conditions  are  observed.  Bat 
while  by  raising  the  temperature  of  the  workroom  the  activity 
of  the  generators  is  increased,  too  low  a  temperature  is  less 
injurious  to  the  regular  course  of  the  process  than  too  high  a 
one. 

The  acme  of  the  formation  of  vinegar  is  at  about  86°  F., 
and  hence  the  aim  should  be  to  maintain  this  temperature  as 
nearly  as  possible  in  the  interior  of  the  generator.  The  tem- 
perature of  the  workroom  must,  however,  be  kept  sufficiently 
low,  so  that  the  acme  in  the  interior  of  the  generator  may  not 
be  exceeded. 

Another  factor  may  here  be  mentioned.  The  closer  the 
temperature  in  the  interior  of  the  generator  approaches  the 
acme  and  the  quicker  the  supply  of  air,  the  more  alcohol  and 
acetic  acid  are  lost  by  evaporation,  or  in  other  words,  the 
smaller  the  yield  of  acetic  acid.  By  the  skillful  utilization  of 
conditions  the  manufacturer  must  aim  to  reduce  this  loss  to  a 
minimum,  and  this  can  be  best  effected  by  a  suitable  arrange- 
ment of  the  workroom.  By  regulating  the  change  of  air  so 
3 


34  MANUFACTURE    OF    VINEGAR. 

that  it  is  not  greater  than  absolutely  necessary,  the  air  will 
soon  become  so  saturated  with  vapors  of  alcohol  and  acetic 
acid  that  no  further  loss  will  take  place  until  the  renewing  of 
the  air  in  the  workroom  appears  necessary.  In  which  manner 
the  manufacturer  is  to  work  in  order  to  carry  on  the  business 
most  advantageously  depends  on  the  conditions  of  trade.  If 
large  orders  have  to  be  filled,  he  will  endeavor  to  increase  the 
capacity  of  the  generators  to  the  utmost  by  maintaining  the 
acme  of  temperature  and  a  vigorous  change  of  air  in  them, 
and  in  this  case  must  submit  to  the  increased  losses  insepar- 
ably connected  with  this  high  performance.  If,  on  the  other 
hand,  he  works  for  stock,  he  will  not  force  the  capacity  of  the 
generators  to  the  utmost,  but  in  order  to  work  as  cheaply  as 
possible  direct  his  attention  to  reduce  the  losses  to  a  minimum. 

Yields  of  Acetic  Acid  Obtained  in  the  Practice — By  keeping 
for  some  time  an  accurate  account  of  the  actual  yields  and 
comparing  them  with  those  theoretically  obtainable,  the 
former  will  be  found  to  fall  more  or  less  short  of  the  latter, 
and  the  difference  will  be  the  smaller,  the  better  the  method 
of  production  in  use. 

In  a  vinegar  factory  occur  many  unavoidable  losses,  the 
sources  of  which  have  been  indicated  in  the  preceding  explana- 
tions ;  alcohol  and  acetic  acid  evaporate,  and  further  a  portion 
of  them  is  entirely  destroyed  by  too  much  oxidation.  Now  a 
loss  by  evaporation,  etc.,  of  ten  per  cent,  of  the  quantity  of 
alcohol  originally  used  must  no  doubt  be  considered  a  large 
one ;  but  from  numerous  observations  it  may  be  asserted  that 
even  'with  the  greatest  care  in  working,  the  loss  in  some  vine- 
gar factories  is  not  less  than  from  15  to  20  percent.,  and  may 
even  be  as  much  as  30  per  cent. 

These  enormous  losses  of  material  conclusively  prove  the 
defectiveness  of  the  processes  in  general  use  and  the  urgent 
necessity  for  reformation.  The  experiments  made  for  this 
purpose,  and  which  have  been  especially  directed  towards  a 
remodeling  of  the  apparatus  used,  cannot  be  considered  en- 
tirely satisfactory,  though  they  were  partially  instituted  by 


PRODUCTS  OF  ACETIC  FERMENTATION.  35 

practical  manufacturers,  who,  however,  lacked  the  necessary 
theoretical  knowledge. 

The  principal  requirement  is  to  provide  the  generator  with 
a  suitable  ventilator,  which  will  allow  of  the  passage  of  ex- 
actly the  quantity  of  air  required  for  the  conversion  of  the 
alcohol  into  acetic  acid,  and  is  so  constructed  that  the  vapors 
of  alcohol  and  acetic  acid  (or  at  least  the  larger  portion)  car- 
ried away  by  the  current  of  air  are  condensed  and  thus  re- 
gained. 

A  vinegar  generator  has  frequently  been  compared  to  a  fur- 
nace, and  in  continuation  of  this  comparison  it  may  be  said, 
that  the  construction  generally  used  is  a  furnace  lacking  every 
arrangement  for  the  regulation  of  combustion.  In  such  a  fur- 
nace as  much  fuel  is  burned  as  corresponds  to  the  quantity  of 
oxygen  entering,  while  in  a  furnace  of  suitable  construction 
the  combustion  of  fuel  can  be  accurately  regulated  by  increas- 
ing or  decreasing  at  will  the  supply  of  air  by  means  of  a 
simple  contrivance. 

A  vinegar  generator  of  suitable  construction  should  be  pro- 
vided with  a  similar  arrangement.  If  the  thermometer  on  the 
apparatus  shows  too  low  a  temperature — hence  too  slow  a  pro- 
cess of  oxidation — the  course  of  the  operation  can  in  a  short 
time  be  accelerated  by  the  production  of  a  stronger  current  of 
air,  and  the  temperature  correspondingly  increased.  If,  on  the 
other  hand,  oxidation  proceeds  too  rapidly,  which  on  account 
of  the  high  temperature  then  prevailing  in  the  apparatus  is 
accompanied  by  considerable  loss  of  substance,  it  can  be 
quickly  reduced  to  within  the  correct  limits  by  decreasing  the 
current  of  air.  An  apparatus  unprovided  with  a  ventilator  is 
left  more  or  less  to  itself,  while  one  provided  with  such  an 
arrangement  is  under  the  entire  control  of  the  manufacturer. 


36  MANUFACTURE    OF    VINEGAK. 


CHAPTER  V. 

METHODS    OF    MANUFACTURE    OF    VINEGAR. 

FROM  what  has  been  previously  said,  two  methods  of  man- 
ufacturing vinegar  can  only  be  distinguished,  namely,  by 
fermentation  and  by  destructive  distillation.  It  has,  however, 
been  deemed  advisable  to  describe  separately  the  old  or  slow 
process  by  fermentation  and  the  new  or  quick  process.  The 
The  various  methods  employed  for  the  manufacture  of  vine- 
gar may  therefore  be  designated  as  follows  : 

1.  By  fermentation  according  to  the  old  or  slow  process. 

2.  By  the  quick  process,  or  manufacture  by  fermentation 
with  the  application  of  improved  methods  in  keeping  with 
our  present  knowledge  of  chemistry. 

3.  Manufacture  of  wood  vinegar,  or  the  preparation  of  acetic 
acid  by  destructive  distillation. 

4.  The  preparation  of  pure  acetic  acid  from  acetates. 

It  would  seem  proper  to  commence  the  description  of  the 
manufacture  of  vinegar  with  the  old  or  slow  process,  but  for 
reasons  of  an  entirely  practical  nature,  it  has  been  concluded 
not  to  do  so,  and  the  quick  process  will  be  first  considered. 

Since  alcoholic  fluids,  directly  formed  by  the  vinous  fer- 
mentation of  sacchariferous  plant  juices,  possess  the  property 
of  changing,  under  circumstances  favorable  to  acetic  fermenta- 
tion, into  vinegar,  it  is  evident  that  the  latter  can  be  prepared 
from  them  and,  in  fact,  it  is  possible  to  prepare  it  from  all 
sweet  fruits  and  parts  of  plants,  such  as  cherries,  strawberries, 
figs,  bananas,  etc.,  as  well  as  from  the  juices  of  the  sugar  cane, 
beet,  chicory  root,  etc. 

Honey,  which  represents  a  concentrated  solution  of  ferment- 
able sugar,  as  well  as  crystallized  cane  sugar,  can  likewise  be 
indirectly  used  for  the  preparation  of  vinegar,  since  solutions 
of  either  can  be  brought  into  vinous  fermentation,  and  the  re- 
sulting alcohol  converted  into  acetic  acid. 


METHODS    OF    MANUFACTURE    OF    VINEGAR.  37 

By  malting  grain,  a  peculiar  body  called  diastase  is  formed, 
which  possesses  the  property  of  converting  starch  into  ferment- 
able sugar,  and  upon  this  fact  is  based  the  manufacture  of  beer 
and  alcohol.  In  an  indirect  manner — the  starch  having  to  be 
converted  first  into  sugar,  and  the  latter  into  alcohol — -it  is 
therefore  possible  to  prepare  vinegar  from  every  substance 
containing  starch,  and  for  this  reason,  we  can  speak  of  grain 
and  malt  vinegars.  The  beer  prepared  from  the  malt  con- 
tains a  certain  quantity  of  alcohol,  and  can  thus  be  directly 
converted  into  vinegar. 

Alcohol  forming  ultimately  the  material  for  the  manufacture 
of  vinegar,  the  direct  use  of  dilute  alcohol  became  obvious. 
By  the  employment  of  a  suitable  process,  i.  e.,  one  correspond- 
ing to  the  laws  of  acetic  fermentation,  it  was  found  that  the 
conversion  of  dilute  alcohol  into  acetic  acid  could  be  effected 
in  a  much  shorter  time  than  by  the  old  method,  and  upon 
this  process  is  based  the  quick  process  now  in  general  use. 
Hence,  as  previously  stated,  two  principal  methods  of  manu- 
facture may  be  distinguished,  viz.  :  the  old  or  slow  process, 
which  requires  more  time,  and  the  new,  or  quick  process. 

In  the  old  process  many  modifications  are  found,  which  are 
partially  based  upon  old  usage  and  partially  upon  the  differ- 
ence in  the  chemical  composition  of  the  raw  material  used. 
Beer,  for  instance,  which  contains  only  about  4  per  cent,  of 
alcohol  and  a  large  quantity  of  extractive  substances  (sugar, 
dextrin,  salts,  etc.),  requires  a  different  treatment  from  wine, 
which  contains  on  an  average  10  per  cent,  of  alcohol,  but 
scarcely  2  per  cent,  of  extractive  substances.  Fruit-wines, 
(cider,  etc.),  with  only  5  to  6  per  cent,  of  alcohol  but  a  large 
quantity  of  extractive  substances,  again  require  different  treat- 
ment from  grape  wine,  etc.,  so  that,  in  a  certain  sense,  it  may 
be  said  there  are  as  many  different  methods  of  making  vin- 
egar as  there  are  fundamental  materials,  and  by  taking  into 
consideration  the  difference  in  the  chemical  composition  of  the 
latter,  it  is  evident  that  there  must  be  just  as  many  varieties 
of  vinegar.  Besides  acetic  acid  and  a  certain  amount  of  water, 


38  MANUFACTURE    OF    VINEGAR. 

every  vinegar  contains  other  substances,  which,  though  fre- 
quently only  present  in  very  minute  quantities,  nevertheless 
exert  considerable  influence  upon  its  properties. 

Even  vinegar  obtained  from  dilute  alcohol  shows  differ- 
ences in  odor,  which  depend  on  the  material  used  in  the  pre- 
paration of  the  specific  alcohol.  Potato  alcohol  always  con- 
tains traces  of  potato  fusel  oil  (amyl  alcohol),  while  other  fusel 
oils  are  found  in  alcohol  prepared  from  grain  or  molasses. 
In  the  oxidation  of  the  alcohol  by  the  vinegar  ferment,  these 
fusel  oils  are  also  oxidized  and  converted  into  combinations 
distinguished  by  their  peculiar  and  very  strong  odor. 

Though  these  bodies  occur  in  vinegar  in  such  minute  quan- 
tities that  they  can  scarcely  be  determined  by  chemical  analy- 
sis, an  expert  can  detect  them  by  the  sense  of  smell,  and  from 
the  specific  odor  of  the  vinegar  form  a  conclusive  judgment  as 
to  the  material  used  in  its  preparation. 

The  differences  in  vinegar  from  wine,  fruit,  beer  and  malt 
are  still  more  pronounced,  and  extend  not  only  to  the  odor, 
but  also  to  the  taste.  Besides  a  specific  odoriferous  principle, 
every  kind  of  wine  contains  oenanthic  ether,  tartar,  tartaric 
and  succinic  acids,  glycerin,  and  a  series  of  extractive  sub- 
stances not  thoroughly  known.  The  odoriferous  substances 
and  the  oenanthic  ether  also  undergo  alteration  in  the  oxida- 
tion of  alcohol,  and  are  converted  into  other  odoriferous  com- 
binations with  suclx  a  characteristic  odor  that  wine  vinegar 
can  at  once  be  recognized  as  such  by  it.  On  account  of  the 
presence  of  so  many  substances  each  possessing  a  specific  taste, 
that  of  the  wine  vinegar  must,  of  course,  differ  from  that  of 
pure  dilute  acetic  acid. 

Similar  conditions  prevail  in  fruit-wine,  beer,  malt  extract, 
etc.,  and  hence  vinegar  prepared  from  these  fluids  must  pos- 
sess definite  properties. 


QUICK    PROCESS    OF    MANUFACTURE    OF    VINEGAR.  39 


CHAPTER  VI. 

QUICK    PROCESS    OF    MANUFACTURE    OF    VINEGAR. 

IN  1823  Schiitzenbach  conceived  the  idea  that  by  greatly 
enlarging  the  relative  surfaces  of  contact  Of  the  alcoholic  solu- 
tion and  air  containing  oxygen,  the  process  of  acetification 
would  be  greatly  facilitated.  His  experiments  proved  suc- 
cessful, and  soon  after  the  quick  vinegar  process  was  generally 
adopted.  Analogous  processes  were  nearly  at  the  same  time 
invented,  in  Germany  by  Wagmann,  and  in  England  by  Ham. 

The  principle  involved  of  course  depends  on  an  extreme 
division  of  the  liquid  being  effected.  This  is  very  skilfully 
contrived.  By  making  the  alcoholic  solution  percolate  slowly 
through,  and  diffuse  over,  a  mass  of  shavings,  wooden  blocks, 
pieces  of  coal  or  cork,  etc.,  it  forms  a  very  thin  layer,  present- 
ing a  large  surface,  and  is  therefore  better  adapted  for  the 
chemical  appropriation  of  the  oxygen  in  the  current  of  air 
which  is  transmitted  over  it.  The  mass  of  shavings,  etc., 
serves  not  only  for  the  division  of  the  liquid  into  fine  drops, 
but  also  as  a  carrier  of  the  vinegar  ferment. 

It  will  be  readily  understood  that  this  arrangement  presents 
in  a  high  degree  all  the  conditions  required  for  the  formation 
of  vinegar,  the  vinegar  ferment  upon  the  shavings  acquiring 
from  the  liquid  all  the  substances  required  for  its  nutriment 
and  propagation,  and  by  the  current  of  air  passing  through 
between  the  shavings  is  enabled  to  oxidize  the  alcohol  to  acetic 
acid.  This  process  taking  place  simultaneously  on  thousands 
of  points  in  a  normally  working  generator  explains  why  a 
large  quantity  of  alcohol  can  in  a  comparatively  short  time  be 
converted  into  acetic  acid.  The  term  quick  process  is  hence 
very  appropriate  for  this  method,  it  differing  from  the  older 
slow  process  only  in  less  time  being  required  for  its  execution, 
the  chemical  processes  being  the  same  in  both  cases. 

It  will  be  seen  that  the  generator,  technically  called  "grad- 
uator,"  used  in  the  quick  process  may  be  compared  to  a  fur- 


40  MANUFACTURE    OF    VINEGAR. 

nace  in  which  the  fuel  (in  this  case  the  alcoholic  fluid)  is  in- 
troduced from  above  and  the  air  from  below.  The  spaces 
between  the  shavings,  etc.,  may  be  compared  to  the  interstices 
of  a  grate,  combustion  taking  place  on  the  points  of  contact  of 
the  alcoholic  fluid,  vinegar  ferment  and  air.  The  product  of 
(partial)  combustion — the  vinegar — collects  in  a  reservoir  in 
the  lower  part  of  the  generator. 

Each  generator,  as  previously  stated,  requires  about  0.4  liter 
of  air  per  second,  which  must  ascend  uniformly  from  below 
through  the  mass  of  shavings,  etc.  At  the  first  glance  this 
would  seem  very  simple,  but  its  practical  execution  is  accom- 
panied by  many  difficulties,  and  hence  a  large  number  of  vari- 
ous constructions  of  generators  have  been  proposed  by  which 
this  object  is  claimed  to  be  best  attained. 

Generators — A  peculiarly  constructed  vessel,  called  the  gen- 
erator, is  required  for  the  production  of  vinegar  by  the  quick 
process.  It  is  divided  into  three  spaces  above  one  another, 
the  uppermost  serving  for  the  division  of  the  alcoholic  liquid 
into  many  small  drops  ;  in  the  center  one,  which  forms  the 
largest  part  of  the  apparatus,  the  alcoholic  liquid  is  converted 
into  vinegar,  while  the  lower  one  serves  for  the  collection  of 
the  vinegar. 

The  best  form  of  the  generator  is  that  of  a  truncated  cone. 
This  form  offers  to  the  alcoholic  liquid  in  its  passage  from  the 
upper  part  of  the  generator  the  opportunity  of  spreading  over 
a  constantly  increasing  surface,  and  by  thus  coming  in  con- 
tact with  the  fresh  air  entering  the  lower  part  of  the  apparatus 
its  oxidation  must  evidently  be  promoted.  The  current  of  air 
in  passing  from  below  to  above  yields  a  certain  portion  of  its 
oxygen  in  the  lower  part  of  the  apparatus,  and  if  it  were 
allowed  to  ascend  in  a  vessel  of  a  purely  cylindrical  shape,  the 
alcoholic  fluid  running  down  would  come  in  contact  with  air 
quite  poor  in  oxygen.  Hence  this  evil  must  be  sought  to  be 
overcome  by  the  acceleration  of  the  motion  of  the  air  upwards, 
which  is  accomplished  by  giving  the  vessel  the  form  of  a 
slightly  truncated  cone. 


QUICK    PROCESS    OF    MANUFACTURE    OF    VINEGAR. 


41 


Fig.  3  shows  a  common  form  of  generator.  It  consists  of 
the  wooden  vat  K  provided  with  a  perforated  false  bottom  L 
a  few  inches  from  the  bottom,  and  another  S,  similar  in  struc- 
ture, at  the  same  distance  from  the  top.  The  aperture  A 
serves  for  the  discharge  of  the  fluid  collecting  underneath  the 
false  bottom  L.  The  cover  D,  the  arrangement  of  which  will 
be  described  later  on,  serves  for  regulating  the  drought  of  air 
in  the  generator.  In  the  lower  part  of  the  generator,  holes,  Or 


are  bored.  These  holes  are  intended  for  the  entrance  of  air, 
and  in  number  may  be  as  many  as  desired,  since  the  regula- 
tion of  the  current  of  air  is  not  to  be  effected  on  the  lower 
portion  of  the  apparatus,  but  on  the  cover. 

For  the  construction  of  the  generator  wood  thoroughly 
seasoned  and  as  free  as  possible  from  knots  should  be  used. 
Formerly  oak  was  largely  employed  for  the  purpose  but,  be- 
sides its  being  too  expensive,  it  has  the  disadvantage  of  be- 


42  MANUFACTURE    OF    VINEGAR. 

ing  so  rich  in  extractive  substances  that  a  generator  con- 
structed of  it,  has  to  be  several  times  lixiviated  with  water 
before  use,  as  otherwise  the  vinegar  prepared  in  it  would  for 
a  long  time  acquire  a  disagreeable  tang  and  dark  color. 
Larch  is  an  excellent  wood  for  the  construction  of  generators. 
In  this  country  pitch  pine  is  largely  used,  and  is  well  adapted 
for  the  purpose,  as  it  is  cheap  and  readily  obtainable  every- 
where. It  is  claimed  by  some  manufacturers  that  the  pitch 
pine  protects  fermentation  in  generators  constructed  of  it  from 
the  influence  of  rapid  variations  in  temperature  which  are  of 
frequent  occurrence  in  portions  of  this  country. 

The  hoops  of  the  generators,  as  well  as  all  other  metallic 
parts  in  the  factory,  should  be  coated  with  good  linseed-oil 
varnish  or  asphaltum  lacquer,  and  care  should  be  had  imme- 
diately to  repair  any  injury  to  this  coating,  as  otherwise  heavy 
rusting  is  caused  by  the  vapors  of  acetic  acid  contained  in  the 
air  of  the  work  room. 

There  is  considerable  variation  in  the  dimensions  of  the 
generators,  some  having  only  a  height  of  5  feet,  with  a  lower 
diameter  of  3  feet  3  inches,  and  others  again  a  height  of  20  feet 
or  more,  with  a  diameter  of  up  to  6J  feet.  The  small  gen- 
erators have  the  disadvantage  of  rapidly  yielding  heat  to  the 
exterior,  and  hence  a  correspondingly  high  temperature  must 
be  maintained  in  the  workroom  in  order  to  keep  up  the  proper 
degree  of  heat  in  their  interior.  On  the  other  hand,  generators 
of  considerable  height  have  the  drawback  of  the  shavings, 
etc.,  with  which  the  center  space  is  filled,  becoming  strongly 
compressed  by  their  own  weight,  thus  obstructing  the  proper 
passage  of  the  air.  It  has  been  sought  to  overcome  this  evil 
by  placing  several  false  perforated  bottoms  in  the  generator,  in 
order  to  divide  the  weight  of  the  filling  into  as  many  smaller 
weights  as  there  are  false  bottoms.  But  this  arrangement  is 
also  attended  with  inconveniences,  it  being  difficult  to  main- 
tain a  sufficiently  strong  draught  of  air  in  generators  of  such 
height. 

Some    manufacturers    hold    that   the   production    of   very 


QUICK    PROCESS    OF    MANUFACTURE    OF    VINEGAR.  43 

strong  vinegar  containing  11  to  12  per  cent,  of  acetic  acid  is 
only  possible  in  very  tall  generators.  This  opinion  is,  how- 
ever, unfounded,  the  manufacture  of  very  strong  vinegar  being 
just  as  well  or  rather  better  effected  in  small  generators  than 
in  those  twenty  feet  or  more  high,  which  besides  are  very 
expensive. 

The  manufacture  of  vinegar  should  be  carried  on  in  a  room 
with  a  low  ceiling,  since  even  with  the  best  heating  arrange- 
ment the  temperature  near  the  ceiling  is  always  much  higher 
than  on  the  floor.  However,  with  the  use  of  generators  20 
feet  high,  the  ceiling  of  the  work  room  must  be  at  least  26 
feet  high,  which  makes  it  impossible  to  maintain  a  uniform 
temperature,  as  the  difference  between  the  upper  and  lower 
parts  would  frequently  amount  to  more  than  25°. 

The  most  suitable  generators  are  very  likely  those  with  a 
height  not  exceeding  10  feet,  and  a  lower  diameter  of  about  45 
inches  and  an  upper  one  of  about  35  inches.  A  large  diameter, 
to  be  sure,  contributes  towards  the  maintenance  of  a  uniform 
temperature  in  the  generator,  but  it  has  the  disadvantage  of 
making  it  difficult  for  the  air  to  ascend  uniformly  through  all 
parts  of  the  filling.  This  drawback  is  sought  to  be  evercome. 
by  placing  in  the  center  of  the  generator  a  tube  open  above  and 
below  and  provided  on  the  sides  with  holes.  Such  tube,  how- 
ever, does  not  produce  the  intended  favorable  effect  upon  the 
draught  of  air  in  the  parts  of  the  filling  surrounding  it,  expe- 
rience having  shown  that  the  greater  portion  of  the  warm  cur- 
rent of  air  ascending  in  the  interior  takes  the  nearest  road  to 
the  top,  i.  e.,  through  the  tube,  without  passing  sideways  into 
the  filling.  Every  generator  of  suitable  construction  should  be 
provided  with  a  well-fitting  cover.  In  this  cover,  Fig.  4,  are 
bored,  in  concentric  circles,  holes  which  are  intended  for 
draught  apertures.  If  the  draught  of  air  in  the  interior  is  too 
great,  it  can  be  at  once  diminished  by  closing  a  number  of 
these  holes,  it  being  even  possible  to  direct  it  towards  a  cer- 
tain portion  of  the  filling.  This  arrangement  is,  however,  only 
available  when  the  false  bottom  to  be  described  later  on  is 


44 


MANUFACTURE    OF    VINEGAR. 


either  not  used  or  provided  with  a  number  of  short  vertical 
tubes  which  permit  the  passage  of  the  air. 

Many  generators  are  provided  with  a  number  of  obliquely 
bored  apertures  below  the  false  bottom  through  which  the  air 
can  escape.  This  is,  however,  attended  with  the  disadvantage 
that  a  regular  draught  of  air  only  takes  place  in  the  outer  layers 
of  filling  next  to  the  walls,  while  it  is  not  sufficiently  strong 
in  the  center  of  the  apparatus.  It  is  also  incorrect  to  have  but 
one  air  aperture  in  the  cover,  which  can  be  made  larger  or 
smaller  by  means  of  a  slide.  In  a  generator  thus  arranged,  the 

FIG.  4. 


current  of  air  entering  below  will  naturally  pass  chiefly  through 
the  conical  portion  of  the  filling,  the  base  of  which  is  formed 
by  the  lower  false  bottom  and  the  apex  by  the  draught  aper- 
ture in  the  cover.  The  lower  portion  of  the  filling,  which 
embraces  this  cone,  remains  without  sufficient  ventilation  and 
is  ineffective  as  regards  the  oxidation  of  alcohol. 

In  Figs.  5  and  6  the  hatched  surfaces  terminated  by  the 
dotted  lines  illustrate  the  portions  of  the  generator  in  which, 
with  the  use  of  many  apertures  below  the  false  bottom  and  a 
single  one  in  the  center  of  the  cover,  the.  regular  current  of  air 


QUICK    PROCESS    OF    MANUFACTURE    OF    VINEGAR. 


45 


from  below  to  above  passes.  Although  a  current  of  air  takes 
place  outside  of  these  lines,  it  is  in  most  cases  too  weak,  and 
consequently  the  entire  available  space  of  the  generator  is  not 
sufficiently  utilized. 


FIG.  5. 


FIG.  6. 


m 


Each  generator  may  also  be  entirely  open  below  and  stand 
in  a  shallow  tub,  which  serves  for  the  collection  of  the  vinegar. 
Generally,  however,  the  lower  portion  of  the  generator  itself  is 
used  for  this  purpose,  and  is  provided  with  an  arrangement  for 


FIG.  7. 


the  occasional  discharge  of  the  collected  fluid.  This  can  be 
effected  either  by  a  spigot  fixed  immediately  above  the  bottom 
or,  as  in  Fig.  7,  by  a  glass  tube,  which  bends  upwards  nearly 
as  high  as  the  air-holes  and  then  curves  downward  so  as  to  dis- 


46 


MANUFACTURE    OF    VINEGAR. 


charge  the  liquid,  when  it  rises  as  high  as  the  shelf  in  the 
interior  of  the  apparatus,  into  an  appropriate  vessel  placed  to 
receive  it.  Simple  as  this  arrangement  is,  it  is  scarcely  suit- 
able in  the  practice  on  account  of  its  being  too  liable  to  break- 
age, and  hence  it  is  better  to  provide  the  generator  with  an 
ordinary  spigot,  and  prevent  the  vinegar  from  rising  too  high, 
by  boring  about  J  inch  below  the  draught  apertures  a  hole 
in  which  is  fitted  a  pipe  leading  to  a  tub.  The  vinegar  rising 
to  the  height  of  this  pipe  will  commence  to  run  off,  and  thus 
give  warning  to  empty  the  generator  by  opening  the  spigot. 


In  generators  of  older  construction  a  strong  hoop  is  fixed 
about  one  foot  from  the  top,  on  which  is  placed  a  perforated 
disk  which  serves  for  distributing  the  alcoholic  fluid  as  uni- 
formly as  possible  over  the  entire  filling.  The  disk,  Fig.  8,  is 
perforated  with  numerous  holes  (about  400  with  a  disk  diam- 
eter of  3  feet)  arranged  in  concentric  circles.  These  holes  are 
loosely  filled  with  cotton  wick  or  packthread,  a  knot  being 
made  at  the  top  end  to  keep  them  from  falling  through.  The 
threads  reach  down  to  the  shavings,  and  serve  the  double 
purpose  of  conducting  the  liquid  equally  through  the  body  of 


QUICK    PROCESS    OF    MANUFACTURE    OF    VINEGAR.  47 

the  generator  and  also  of  stopping  it  from  passing  too  rapidly 
through  it  (see  Fig.  9).  It  is  important  to  pack  the  disk  so 
tightly  against  the  walls  of  the  generator  that  none  of  the 
liquid  can  percolate,  which  is  best  effected  by  a  packing  of  tow, 
and  coating  this  with  a  mixture  of  equal  parts  of  wax  and 
rosin.  The  dripping  of  the  alcoholic  fluid  through  the  disk 
taking  place  uniformly  only  when  the  latter  lies  perfectly  hori- 
zontal, great  care  must  be  exercised  in  placing  the  generator. 
To  prevent  warping  several  strong  cross-pieces  are  inserted  in 
the  lower  side  of  the  disk. 

As  previously  mentioned  the  current  of  air  must  pass  through 

FIG.  9. 


all  portions  of  the  filling,  and  for  this  purpose  seven  short  glass 
tubes,  r  (Fig.  8),  about  f  inch  in  diameter,  are  inserted  in  the 
disk.  These  tubes  are  so  arranged  that  one  is  in  the  center  of 
the  disk  and  the  others  in  a  circle  equidistant  from  the  center 
and  the  periphery.  Upon  the  disk  is  placed  the  well-fitting 
cover,  provided  with  an  aperture  for  the  passage  of  the  air. 
This  aperture,  about  3  inches  square,  is  provided  with  a  well- 
fitting  slide,  so  that  it  can  be  made  larger  or  smaller  at  will. 
As  previously  stated,  it  is  more  suitable  to  provide  the  cover 
with  a  large  number  of  draught  holes  arranged  in  concentric 
circles  and  to  fit  each  hole  with  a  wooden  stopper.  By  with- 
drawing or  inserting  the  stoppers  the  draught  of  air  can  then 
be  properly  regulated. 

To  effect  the  influx  of  air  from  below  in  such  a  manner  that 
it  takes  place  not  only  through  the  draught  holes  in  the  circum- 
ference, but  also  assures  its  conveyance  to  the  center  of  the 
apparatus,  it  is  recommended  to  insert  in  the  center  of  the 
lower  part  in  which  the  fluid  collects  a  tube,  R,  Fig.  10,  open 


48 


MANUFACTURE    OF    VINEGAR. 


at  both  ends  and  protected  above  by  the  hood  H  against  the 
dropping  in  of  alcoholic  liquid. 

A  uniform  distribution  of  the  alcoholic  liquid  upon  all  por- 
tions of  the  filling  of  the  apparatus  would  be  effected  if  about 


FIG.  10. 


the  same  quantity  of  liquid  dripped  from  all  the  threads.  This 
being,  however,  difficult  to  attain,  it  has  been  sought  to  give 
the  disk  a  more  suitable  arrangement,  which  consists,  for  in- 
stance, in  the  insertion  of  small  wooden  tubes  with  a  small 


FIG.  11. 


I 


aperture  on  the  side  (Fig.  11).  This  arrangement,  though 
very  suitable  in  itself,  becomes,  however,  useless  in  case  of  the 
slightest  warping  of  the  disk,  a  number  of  the  tubes  being 
then  raised  so  high  that  no  fluid  runs  through  them,  while  it 
passes  in  a  full  stream  through  the  others. 


QUICK    PROCESS    OF    MANUFACTURE    OF    VINEGAR. 


49 


These  drawbacks  connected  with  the  use  of  a  disk  can  be 
somewhat  diminished  by  the  employment  of  a  so-called  "  tilt- 
ing trough  "  (Figs.  12  and  13),  which  is  arranged  as  follows  : — 

Upon  a  perfectly  horizontal  axis  is  placed  a  rotatory,  trough- 
like  vessel  divided  by  a  partition  into  two  equal  parts. 

If  the  tilting  trough  is  in  the  position  shown  in  Fig.  12,  the 
alcoholic  liquid  runs  through  the  cock,  placed  above,  into  the 
partition  marked  1. 

As  soon  as  this  partition  is  filled  to  a  certain  height  it  turns 
ovef  in  consequence  of  the  disturbance  of  the  equilibrium  of 
the  trough  and  assumes  the  position  shown  in  Fig.  13.  In 
this  position  partition  2  is  gradually  filled  with  alcoholic 
liquid  ;  the  trough  then  tilts  back  into  position  1,  and  so  on. 


FIG.  12. 


FIG.  13. 


It  will  be  seen  that  with  the  assistance  of  such  a  tilting 
trough  the  same  quantities  of  liquid  can  always  be  poured  out 
at  certain  intervals,  and  that  this  arrangement  can  be  used  for 
distributing  the  alcoholic  liquid  upon  the  disk,  the  latter  in 
this  case  being  best  provided  with  holes  having  the  form  of  an 
inverted  cone.  The  apex  of  this  cone  forms  a  very  narrow 
aperture  through  which  the  alcoholic  liquid  poured  upon  the 
disk  trickles  in  very  thin  jets  upon  the  filling  of  the  generator. 

But  even  this  arrangement  is  not  free  from  objections,  it 
working  entirely  satisfactorily  only  as  long  as  the  disk  remains 
in  a  perfectly  horizontal  position.     In  the  more  modern  con-  > 
structions  of  vinegar  generators  the  disk  is  generally  entirely  I 
4 


50 


MANUFACTURE    OF    VINEGAR. 


omitted  and  the  distribution  of  the  alcoholic  liquor  effected  by 
a  so-called  "  sparger,"  similar  to  the  one  used  in  beer  brewing 
for  sprinkling  malt  residues.  The  sparger  is  arranged  like  a 
simple  turbine,  and  is  moved  by  reaction  in  the  direction 
opposite  to  that  in  which  the  discharge  of  the  fluid  takes  place. 
Spargers  used  in  vinegar  factories  can  be  constructed  only  of  a 
material  indifferent  to  the  action  of  acetic  acid,  such  as  wood, 
glass,  hard  rubber,  etc.  Their  construction  will  be  understood 

FIG.  14. 


from  Figs.  14  and  15,  showing  a  view  from  above  and  a  cross- 
section. 

Into  a  hollow  cylinder  of  wood  are  screwed  four  thin  wooden 
tubes,  closed  at  both  ends  and  perforated  ^lengthwise  with 
numerous  small  holes.  The  tubes  are  so  arranged  that  all  the 
holes  are  directed  toward  one  side.  The  basin  in  the  center  is 
closed  on  top  by  a  glass  tube  about  20  inches  long  and  of 
sufficient  width  to  allow  of  the  passage  of  as  much  fluid  as  can 
at  one  time  run  off  through  all  the  lateral  tubes. 


QUICK    PROCESS    OF    MANUFACTURE    OF    VINEGAR. 


51 


The  principal  requisite  of  the  correct  working  of  the  sparger 
is  that  it  revolves  with  ease  around  its  vertical  axis.  This  is 
effected  by  placing  in  the  center  of  the  vessel  a  glass  pin  drawn 
out  to  a  fine  point  and  running  in  a  small  glass  step.  The 


FIG.  15. 


vertical  glass  tube  is  guided  in  a  sharp-edged  wooden  ring 
fastened  to  a  stay  placed  upon  the  cover  of  the  generator  (Fig. 
16).  The  sparger  finds  its  center  of  motion  upon  a  strip  in- 
serted in  the  direction  of  the  diameter  of  the  generator.  This 
strip  is  placed  at  such  a  height  that  the  sparger  can  move 


FIG. 


freely  between  it  and  the  cover  of  the  generator.  The  sparger 
being  in  position  as  shown  in  Fig.  16,  a  funnel-shaped  vessel, 
through  which  the  alcoholic  fluid  is  poured  in,  is  placed  upon 
the  glass  tube. 


52  MANUFACTURE    OF    VINEGAR. 

By  now  pouring  through  this  funnel-shaped  vessel  the  alco- 
holic liquid  in  a  sufficiently  strong  stream,  so  that  during  its 
influx  the  glass  tube  remains  filled,  it  passes  in  fine  jets 
through  the  lateral  openings,  and,  the  sparger  revolving  in  an 
opposite  direction,  is  distributed  in  the  form  of  a  fine  spray 
over  the  filling  in  the  generator. 

The  use  of  the  sparger  overcomes  the  difficulties  frequently 
occurring  with  the  disk,  especially  as  regards  the  position  of 
the  latter,  and  the  circulation  of  air  through  the  apparatus  also 
takes  place  in  a  perfectly  uniform  manner.  A  number  of 
apertures  in  the  cover  of  the  generator  serve  also  here  for  the 
regulation  of  the  current  of  air. 

A  thermometer  is  an  indispensable  adjunct  to  a  generator, 
and  should  be  so  placed  that  the  temperature  prevailing  in  the 
apparatus,  and  especially  in  the  center,  can  be  readily  read 
off.  This  is  best  effected  by  introducing  at  about  half  the 
height  of  the  apparatus,  through  an  obliquely  bored  hole  in 
one  of  the  staves,  a  glass  tube  closed  at  the  lower  end  and 
reaching  to  the  center  of  the  filling.  This  tube  serves  for  the 
reception  of  a  thermometer  fastened  to  the  lower  end  of  a  stick 
of  wood.  The  latter  projects  from  the  glass  tube,  so  that  the 
thermometer  can  be  quickly  drawn  out  and  the  temperature 
read  off. 

Filling  the  generators. — The  space  between  the  upper  disk 
and  lower  false  bottom  is  filled  with  a  material  offering  a  large 
surface  for  the  distribution  of  the  alcoholic  liquid.  Pieces  of 
charcoal  and  of  pumice  washed  in  hydrochloric  acid  and  well 
rinsed  in  water  to  remove  empyreurnatic  substances,  which 
would  render  induction  of  acetic  fermentation  impossible, 
have  been  used  for  the  purpose.  Small  pieces  of  cork  and 
cork  waste  have  also  been  recommended  for  filling.  This 
material  absorbs  liquids  like  a  sponge,  but  when  sucked  full 
does  not  press  evenly  together,  dry  places  being  thus  formed 
during  the  operation.  Corn  cobs  thoroughly  dried  and  finely 
divided  may  be  used  to  advantage,  especially  in  the  manufac- 
ture of  wine  and  cider  vinegar.  Grape  stems  are  still  occa- 


QUJCK    PROCESS    OF    MANUFACTURE    OF    VINEGAR.  53 

sionally  used.  They  actually  present  a  very  large  surface 
but,  independent  of  the  fact  that  they  cannot  be  everywhere 
obtained  in  sufficient  quantities,  they  have  the  drawback  of 
becoming  in  a  short  time  so  firmly  compressed  as  to  prevent 
the  free  passage  of  air. 

Beechwood  shavings,  however,  are  now  almost  generally  em- 
ployed for  filling  the  generators.  Indeed,  beechwood  presents 
many  advantages:  It  can  be  had  easily  and  is  cheap;  it  curls 
well  and  stands  without  breaking  for  a  length  of  time.  White 
woods  will  curl  as  well,  but  they  will  not  stand  so  well  as 
beech  ;  resinous  woods  are  not  porous  enough,  and  besides 
their  rosin  is  objectionable,  as  it  may  partly  dissolve  in  the 
vinegar ;  oak  wood  does  not  curl  as  well  and  contains  too 
much  coloring  matter  and  tannin. 

The  beech  shavings  are  generally  made  in  special  factories. 
They  consist  of  wooden  bands  about  0.02  inch  thick,  1 J  inches 
wide,  and  16  to  20  inches  long.  They  are  rolled  into  close 
spirals  by  a  special  machine,  and  each  shaving,  according  to 
the  above  dimensions,  presents  a  surface  of  about  62  square 
inches.  Now,  as  a  generator  of  moderate  size  contains  many 
thousands  of  such  shavings,  it  will  be  readily  seen  that  the 
surface  over  which  the  alcoholic  fluid  is  distributed  is  an 
extraordinarly  large  one. 

A  shaving  of  the  stated  dimensions  represents  in  a  rolled 
state  a  cylinder  with  a  volume  in  round  numbers  of  1.7  cubic 
inches.  By  allowing  an  interspace  of  .85  cubic  inch  between 
the  shavings,  1.7  -f-  0.85  =  1.92  cubic  inches  space  is  required 
for  each  shaving.  The  space  to  be  filled  with  shavings  in  a 
generator  3.28  feet  in  diameter  and  6.56  feet  high  is  equal  to 
55.44  cubic  feet,  and  hence  58,000  shavings,  with  a  total  sur- 
face of  22,733.56  square  feet,  are  required  for  the  purpose. 
Now  suppose  only  5  per  cent,  of  this  surface  is  continually 
active  in  the  formation  of  vinegar,  we  have  still  a  surface  of 
over  1075  square  feet  at  our  disposal.  But  the  active  surface 
would  seem  to  be  actually  much  smaller  even  with  the  most 
favorable  working  of  the  generator,  as  otherwise  the  average 


54  MANUFACTURE    OF    VINEGAR. 

quantity  of  alcohol  daily  converted  into  acetic  acid  in  a  gen- 
erator would  be  much  larger  than  is  actually  the  case. 

Beechwood  shavings  contain  a  considerable  quantity  of  ex- 
tractive substances,  which  if  not  removed,  would  for  a  long 
time  impart  a  disagreeable  tang  (woody  taste)  to  the  vinegar. 
Hence  it  is  recommended  to  lixiviate  the  shavings  in  water 
repeatedly  renewed,  in  order  to  get  rid  of  the  substances 
soluble  in  cold  water,  and  remove  the  last  traces  of  them  by 
treatment  with  steam. 

This  steaming  is  best  effected  in  a  large  tub  or  vat,  which  is 
later  on  to  be  used  as  a  generator.  The  shavings  are  thrown 
in  loosely  and  covered  with  a  loaded  lid.  A  steam-pipe  is 
introduced  through  a  hole  near  the  lid,  and  the  tap-hole  near 
the  bottom  is  opened.  The  steam-pipe  being  connected  with  a 
boiler,  in  which  prevails  a  tension  of  1J  to  2  atmospheres,  the 
steam-cock  is  at  first  opened  but  slightly,  to  prevent  the  steam 
entering  with  great  force  from  throwing  off  the  lid,  or  even 
bursting  the  vessel.  In  the  commencement  of  the  operation 
the  steam  condenses  on  the  shavings,  but  after  some  time  the 
vessel  becomes  very  hot,  and  a  dark-colored  fluid,  consisting 
of  almost  boiling  water  charged  with  extractive  substances  of 
the  wood,  begins  to  run  off.  After  continuous  steaming  for 
about  20  to  60  minutes — according  to  the  size  of  the  vessel — 
the  fluid  running  off  becomes  clearer  until  finally  clear  water 
is  discharged,  which  is  indicative  of  the  removal  of  the 
extractive  substances  soluble  in  water. 

Although  not  absolutely  necessary,  it  is  advisable  to  dry  the 
steamed  shavings.  When  air-dry  they  still  contain  about  20 
per  cent,  of  water,  which  in  the  subsequent  "  acetification  "  of 
the  generator  must  be  replaced  by  vinegar.  Hence  it  is 
recommended  to  dry  the  shavings  completely  by  exposing 
them  for  some  time  to  a  current  of  air  of  194°  to  212°  F. 

In  a  factory  provided  with  a  central  heating  apparatus  *  in 
the  cellar,  this  drying  of  the  shavings  can  be  effected  without 

*The  arrangement  of  a  central  heating  apparatus  will  be  described  later  on  in 
speaking  of  the  arrangement  of  the  factory. 


QUICK    PROCESS    OF    MANUFACTURE    OF    VINEGAR.  55 

difficulty,  it  only  being  necessary  to  put  them  in  a  vessel  with 
a  perforated  bottom  and  open  on  top,  and  place  the  vessel 
over  an  aperture  of  the  register  through  which  the  hot  air 
from  the  heating  apparatus  ascends,  closing  all  other  apertures. 

As  perfectly  dry  wood  absorbs  with  avidity  moisture  from 
the  atmosphere,  the  shavings  thus  dried  should  immediately 
be  brought  into  another  vessel  and,  while  still  hot,  moistened 
with  the  vinegar  intended  for  acetification. 

Before  using  the  shavings  for  filling  the  generators,  it  is 
necessary  to  allow  them  to  swell  by  placing  them  in  water  or 
alcoholic  liquid.  If  this  were  omitted  and  the  shavings  in- 
troduced in  a  dry  state,  they  would  rise  above  the  generators 
as  soon  as  moistened,  on  account  of  the  increase  in  volume 
by  swelling. 

In  most  factories  it  is  customary  simply  to  pour  the  shav- 
ings into  the  generator,  but  for  a  uniform  distribution  of  the 
alcoholic  fluid  it  is  advisable  to  proceed  with  the  filling  in  a 
certain  order.  First  place  the  shavings  in  three  or  four  regu- 
lar layers  upon  the  false  bottom,  then  pour  them  in  loosely  to 
a  height  of  8  to  12  inches,  and  after  leveling  the  surface  as 
much  as  possible  pour  in  again,  and  continue  in  this  manner 
until  the  generator  is  filled.  The  uppermost  portion  should 
again  consist  of  three  or  four  regular  layers. 

All  the  generators  used  in  a  vinegar  factory  should  be  of 
the  same  size  and  charged  with  the  same  number  of  shavings, 
which  is  best  effected  by  filling  them  with  the  same  quantity 
by  weight.  The  total  surface  of  shavings  being  thus  nearly  the 
same  in  all  generators,  the  latter  will  work  uniformly,  i.  e.,  with 
an  equal  temperature  and  draught  of  air;  and  in  the  same  time 
convert  equally  large  quantities  of  alcohol  into  acetic  acid. 


56  MANUFACTURE    OF    VINEGAR. 

CHAPTER  VII. 

ARRANGEMENT    OF    A    VINEGAR    FACTORY. 

THE  arrangement  of  the  manufacturing  rooms  formerly  cus- 
tomary even  in  large  factories  is  by  no  means  a  suitable  one. 
The  generators  were  generally  simply  placed  in  a  room  adapted 
for  the  purpose  by  its  size,  while  the  high  temperature  re- 
quired was  sought  to  be  maintained  by  heating.  By  con- 
sidering, however,  that  every  considerable  variation  in  the 
temperature  causes  also  a  disturbance  in  the  formation  of 
vinegar,  it  will  be  seen  that  the  object  of  keeping  up  an  undis- 
turbed working  of  the  factory  cannot  be  attained  by  such 
primitive  means.  A  suitable  arrangement  of  the  room  in 
which  the  vinegar  is  to  be  manufactured  is,  therefore,  abso- 
lutely necessary. 

The  principal  requisites  to  be  observed  are  :  The  mainten- 
ance of  a  uniform  temperature  in  the  room  and  a  suitable 
arrangement  for  ventilation.  Further,  simple  devices  for  the 
conveyance  of  the  raw  materials  and  the  finished  product 
must  be  provided  for,  and  means  devised  for  regaining  the 
acetic  acid,  with  the  vapors  of  which  the  air  in  the  manufac- 
turing room  is  constantly  saturated. 

For  the  maintenance  of  a  uniform  temperature  in  the  work- 
room, which  should  remain  almost  constant  even  in  the  cold- 
est season  of  the  year  and  during  abrupt  changes  in  the  outer 
temperature,  the  waljs  should  be  of  more  than  ordinary  thick- 
ness and  the  number  of  windows  and  doors  sufficient  only  for 
the  necessary  light  and  communication,  and  so  arranged  that 
no  unintentional  ventilation  can  occur.  The  windows  and 
doors  should,  therefore,  be  double,  and  the  latter  so  placed 
that  one  can  be  closed  without  opening  the  other.  The  walls 
and  ceilings  should  be  plastered  and  preferably  papered  with 
heavy  packing  paper  ;  asbestus  shingles  are  also  highly  recom- 
mended for  this  purpose. 


ARRANGEMENT    OF    A    VINEGAR    FACTORY.  57 

Asphaltum  being  impermeable  and  also  indifferent  to  the 
action  of  acetic  acid,  is  undoubtedly  the  best  material  for  the 
floor  of  the  workroom,  though  it  may  also  be  constructed  of 
large  slabs  of  sandstone  with  the  joints  filled  in  with  asphal- 
tum.  Cement  floors  can  only  be  recommended  provided  they 
are  immediately  after  their  construction  coated  with  silicate  of 
soda  until  they  cease  to  absorb  it.  In  constructing  the  floor 
care  must  be  had  to  give  it  such  an  inclination  that  the  entire 
surface  can  be  cleansed  by  a  simple  jet  of  water.  If  the  heat- 
ing channel  is  conducted  lengthwise  through  the  workroom, 
gutters  for  the  rinsing  water  to  run  off  must  be  arranged  on 
both  sides. 

The  height  of  the  room  depends  on  that  of  the  generators. 

Heating  of  the  Workroom — Heating  by  a  stove  placed  in  the 
workroom  itself  can  only  be  recommended  for  very  small  fac- 
tories ;  in  larger  ones  a  special  heating  apparatus  should  always 
be  provided.  Where  stoves  are  used  it  is  recommended  to 
arrange  them  so  that  the  fuel  can  be  supplied  and  the  ashes 
removed  from  the  outside,  i.  e.,  from  a  room  adjoining  the 
actual  workroom.  In  attending  to  the  stoves  fine  particles  of 
ashes  will  unavoidably  reach  the  air,  and  from  the  latter  they 
may  get  into  the  generators,  and  being  soluble  in  acetic  acid 
may  injure  the  vinegar  ferment. 

For  large  factories  a  heating  apparatus  similar  to  the  one 
shown  in  Figs.  17  and  18  can  be  recommended.  The  heater, 
provided  with  the  feeding-door  H  and  the  air-regulating  door 
A,  stands  in  a  vault  beneath  the  center  of  the  room  to  be 
heated.  It  is  surrounded  on  all  sides  by  the  sheet-iron  jacket 
Mt  reaching  from  the  floor  of  the  cellar  to  the  top  of  the  vault. 
In  the  vault  is  a  circular  aperture,  0,  for  the  reception  of  the 
flues  C  and  Ci.  The  latter  ascending  slightly,  run  along  the 
center  of  the  room  to  be  heated.  Above  they  are  covered  by 
cast-iron  plates,  P,  and  by  pushing  these  plates  apart  or  sub- 
stituting a  lattice  plate  for  one  of  them  in  any  part  of  the  flue, 
warm  air  can  be  admitted  to  the  room.  If  the  room  is  to  be 
heated  without  renewing  the  air,  the  register  in  the  flue  L, 


OO  MANUFACTURE    OF    VINEGAR. 

which  communicates  by  a  flat  iron  pipe  with  the  lower  part  of 
the  jacket,  is  opened.  The  furnace  being  heated,  the  air  in  the 
room  is  sucked  in  the  direction  of  the  arrow  through 'the  flue 
L,  and  passing  between  the  jacket  and  the  furnace,  ascends 
strongly  heated  through  0  and  penetrates  through  the  open- 
ings in  the  flue,  air  being  again  sucked  through  L,  and  so  on. 

FIGS.  17,  18. 


If,  however,  the  air  in  the  workroom  is  to  be  entirely  re- 
newed, the  air-flue  L  is  closed  and  a  register  (not  shown  in 
the  illustration)  in  the  lower  part  of  the  jacket  opened.  In 
this  case  the  air  in  the  cellar  is  sucked  in,  heated  and  distrib- 
uted through  the  flues  C  and  Cj.  By  partially  opening  this 


ARRANGEMENT    OF    A    VINEGAR    FACTORY. 


59 


FJG.  19. 


register  and  that  in  L,  a  portion  of  the  air  can  be  renewed  at 
will. 

In  order  to  be  able  to  form  a  correct  idea  of  the  state  of  the 
temperature  prevailing  in  the  room,  it  is 
advisable  to  have  several  ordinary  thermom- 
eters and  also  a  maximum  and  minimum 
thermometer.  If  the  latter  shows  no  greater 
variation  than  from  4°  to  5°,  the  process  of 
heating  may  be  considered  as  satisfactory. 

A  very  suitable  apparatus  for  controlling 
the  temperature  in  a  vinegar  factory  is  an 
electrical  thermometer,  which  is  so  arranged 
that  a  bell  rings  in  case  the  temperature 
rises  above  or  falls  below  a  certain  degree. 
By  placing  two  such  thermometers  in  the 
room,  the  bell  of  the  one  indicates  the  rise 
of  the  temperature  above  the  limit,  and  that 
of  the  other  that  it  has  fallen  below  it. 

Fig.  19  illustrates  the  principle  of  a  maxi- 
mum electrical  thermometer,  i.  e.,  one  which 
rings  a  bell  when  the  temperature  of  the 
room  exceeds  a  certain  limit.  Into  the  bulb 
of  an  ordinary  mercury  thermometer  is 
melted  a  platinum  wire  ;  another  platinum 
wire. is  inserted  in  the  tube  up  to  the  mark 
indicating  the  temperature  not  to  be  ex- 
ceeded, for  instance,  35°  C.  The  ends  of 
the  platinum  wires  projecting  from  the  ther- 
mometer are  connected  by  insulated  copper 
wires  with  a  galvanic  battery  consisting  of  several  elements, 
an  ordinary  door-bell  being  inserted  in  one  part  of  the  con- 
ductor. If  now,  in  consequence  of  a  continued  increase  in  the 
temperature,  the  mercury  rises  to  the  point  of  the  platinum 
wire  at  the  figure  35°,  the  circuit  of  the  battery  is  closed  at 
the  same  time  by  the  column  of  mercury,  and  the  bell  rings 
and  keeps  ringing  until  the  circuit  is  again  opened  by  the 
mercury  falling  below  35°. 


45 


-20 


—  15 


60          •  MANUFACTURE    OP    VINEGAR. 

The  minimum  electrical  thermometer,  used  for  indicating 
the  falling  of  the  temperature  below  a  certain  degree,  is  so 
arranged  that  one  platinum  wire  is  melted  into  the  bulb  of  the 
thermometer  and  the  other  in  the  tube  at  the  point  below 
which  the  temperature  is  not  to  fall.  As  long  as  the  mercury 
remains  above  this  point  a  battery,  which  changes  a  piece  of 
iron  to  an  electro-magnet,  whose  armature  opens  a  second  bat- 
tery which  is  connected  with  an  electric  bell,  remains  closed. 
If  the  temperature  falls  below  the  minimum,  the  circuit  of 
the  first  battery  is  opened,  and  the  armature  of  the  electro- 
magnet falling  down  effects  the  closing  of  the  second  battery 
and  sets  the  bell  ringing. 

By  placing  such  thermometers  not  only  in  the  working 
room  but  also  in  every  generator,  the  control  of  the  entire 
process  would  be  immensely  facilitated,  but  at  the  present 
time  these  useful  and  at  the  same  time  inexpensive  instru- 
ments are  but  little  used  in  vinegar  factories. 

In  factories  arranged  according  to  the  automatic  system,  the 
alcoholic  liquid  is  contained  in  vessels  placed  at  such  a  level 
that  their  contents  can  run  directly  into  the  generators.  The 
alcoholic  liquid  having  to  be  correspondingly  heated,  adequate 
provision  must  be  made  for  heating  the  space  in  which  the 
reservoirs  are  placed.  In  order  not  to  increase  the  height  ot 
the  entire  room,  it  is  recommended  to  place  these  vessels  in 
the  center  and  give  only  to  this  portion  the  required  height. 
This  has  the  further  advantage  that  the  alcoholic  liquid  can 
be  pumped  up  by  the  use  of  a  pump  with  a  short  rising-pipe, 
and  the  liquid  can  be  readily  conducted  from  the  reservoirs 
to  the  separate  generators  by  means  of  pipes. 


ARTIFICIAL    VENTILATION    OF    VINEGAR    GENERATORS.        61 

CHAPTER  VIII. 

ARTIFICIAL  VENTILATION   OF  THE  VINEGAR  GENERATORS. 

THE  first  experiments  in  conveying  direct  air  to  every  gen- 
erator were  made  in  England  ;  but  though  this  step  towards 
improvement  in  making  vinegar  must  be  considered  an 
important  advance,  the  English  process  failed  of  being  ac- 
cepted in  practice  on  account  of  the  inadequacy  of  the 
apparatus  used. 

In  the  English  factories  by  a  special  apparatus  a  current  of 
air  was  sucked  from  above  to  below  through  every  generator. 
As  shown  in  Fig.  20,  the  tall  generator  is  open  on  top  and 
divided  into  several  partitions  by  false  bottoms,  upon  which  the 
shavings,  etc.,  rest.  Above  each  false  bottom  holes  are  bored 
in  the  circumference  of  the  generator.  In  the  bottom  of  the 
generator  is  inserted  a  pipe  which  is  connected  with  an 
arrangement  for  sucking  in  the  air,  a  blower  or  air-pump 
being  used  for  the  purpose. 

As  will  be  seen  from  the  illustration,  the  suction  of  air 
through  all  parts  of  the  generator  cannot  be  uniformly  effected 
by  the  use  of  this  apparatus,  the  current  of  air  being  much  more 
checked  in  the  upper  portions  by  the  false  bottoms  and  holes 
in  the  circumference,  than  in  the  lower.  Hence  the  effect  of 
the  air-pump  or  blower  will  chiefly  assert  itself  in  the  lowest 
partition.  This  drawback  might  be  remedied  by  leaving  out 
the  false  bottoms  and  placing  no  air-holes  in  the  circumference 
of  the  generator  entirely  open  at  the  top.  By  this  means  the 
air  would  be  forced  to  pass  in  a  uniform  current  through  the 
entire  layer  of  the  filling  material. 

That  the  passage  of  the  current  .of  air  from  above  to  below 
is  entirely  incorrect,  because  contrary  to  all  theoretical  require- 
ments, can  readily  be  explained:  In  a  generator  in  full  activity, 
oxidation  of  alcohol  must  already  take  place  in  the  uppermost 
portion,  and  hence  a  certain  quantity  of  oxygen  is  withdrawn 


62 


MANUFACTURE    OF    VINEGAR. 


FIG.  20. 


from  the  air.  This  process  being  also  continued  in  the  lower 
parts  of  the  generator,  a  current  of  air  already  deprived  of  a 
portion  of  its  oxygen,  and  hence  less  suitable  for  the  further 

formation  of  acetic  acid,  would  be 
sucked  in  the  same  direction  which 
the  drops  of  alcohol  take. 

The  principal  reason  advanced 
for  the  use  of  a  current  of  air  from 
above  to  below  is  that  by  these 
means  a  uniform  temperature  is 
maintained  in  all  parts  of  the  gen- 
erators, while  it  rises  considerably 
in  the  upper  part  of  those  in  which 
the  air  passes  from  below  to  above. 
This  rise  of  temperature  is,  however, 
agreeable  to  nature.  The  air  enter- 
ing from  below  oxidizes  the  alcohol 
to  acetic  acid,  becoming  thereby 
poorer  in  oxygen  and  again  heated. 
By  the  higher  temperature  it  ac- 
quires, it  is,  however,  capable  of  a 
more  vigorous  chemical  activity,  so 
that  it  will  induce  the  process  of  the 
formation  of  vinegar,  even  in  the 
uppermost  portions  of  the  genera- 
tor. Besides,  the  warmer  current 
of  air  moving  upwards  has  the  fur- 
ther advantage  of  yielding  heat  to 
the  drops  of  alcoholic  fluid  trickling  down.  With  the  use  of 
generators  of  moderate  height,  and  with  a  suitable  regulation 
of  the  draught  of  air,  the  maximum  temperature  will  not  be 
exceeded,  even  in  the  uppermost  portions  of  the  generator. 

If  no  rise  of  temperature  is  observed  in  the  lower  portions 
of  a  generator  in  which  the  air  passes  from  above  to  below,  it 
only  proves  that  the  air  has  lost  too  much  oxygen  to  further 
effect  a  vigorous  oxidation  of  the  alcohol.  It  will  be  readily 


ARTIFICIAL    VENTILATION    OF    VINEGAR    GENERATORS.        68 

understood  that  under  these  conditions  a  diminution  in  the 
loss  of  substance  can,  to  a  certain  degree,  be  effected,  but  it  i& 
doubtful  whether  the  generators  are  utilized  in  the  manner 
they  should  be ;  besides,  the  diminution  in  loss  of  substance 
cannot  be  very  considerable.  Since  a  high  temperature  also 
prevails  in  ventilated  generators,  the  current  of  air  passing 
downward  will  be  loaded  with  as  much  vapor  of  alcohol  or  of 
acetic  acid  as  it  can  absorb  at  this  temperature,  and,  hence,  it 
would  seem,  no  diminution  in  loss  by  evaporation  could  be 
effected.  To  render  this  possible,  the  current  of  air  sucked 
from  the  generator  would  have  to  be  sufficiently  cooled  off  by 
a  suitable  arrangement  to  allow  of  the  greater  portion  of  the 
vapors  carried  away  by  the  current  of  air  being  condensed  to 
a  fluid. 

Schulze's  Ventilating  Apparatus. — The  ventilation  of  the  vine- 
gar generators,  according  to  the  previously  described  method, 
requires  the  presence  of  an  uninterruptedly  acting  power  for 
working  the  air-pump,  blower,  etc.  As  is  well  known,  a  cur- 
rent of  air  can,  however,  be  also  produced  by  heating  the  air 
passing  through  an  ascending  pipe,  by  which  it  becomes 
specifically  lighter  and  ascends,  while  denser  air  enters  from 
below,  etc.  Schulze,  as  will  be  seen  from  Fig.  21,  has  applied 
this  method  to  the  ventilation  of  vinegar  generators. 

Schulze's  generator  differs  somewhat  from  the  ordinary  con- 
struction, and  is  arranged  as  follows  :  The  vat  has  a  height  of 
about  8  feet,  and  a  diameter  of  2  feet  6  inches.  In  the  upper 
part  it  is  terminated  by  a  false  head,  fitting  air-tight,  and  is 
further  provided  with  a  cover,  in  the  center  of  which  is  an 
aperture  about  2J  inches  in  diameter,  which  serves  for  the 
entrance  of  air,  while  another  aperture  on  the  side  serves  for 
pouring  in  the  alcoholic  liquid.  In  the  false  head  are  in- 
serted four  glass  tubes,  open  at  both  ends,  and  about  f  inch  in 
diameter,  which  afford  a  passage  to  the  air.  The  generator  is 
filled  with  pieces  of  washed  and  assorted  charcoal,  so  that 
pieces  of  the  size  of  a  nut  are  placed  upon  the  false  bottom, 
and  upon  this  smaller  pieces,  gradually  decreasing  in  size 


64 


MANUFACTURE    OF    VINEGAR. 


until  those  on  the  top  are  only  that  of  a  pea.  In  the  center 
of  the  bottom  is  inserted  a  wooden  tube,  open  at  both  ends 
and  provided  on  top  with  a  hood  to  prevent  the  trickling  in 
of  vinegar  (see  Fig.  10).  By  a  suitable  intermediate  piece, 
this  tube  is  connected  with  the  draught-pipe  (see  Fig.  21),  in 
which  the  ascension  of  the  air  by  heating  is  effected. 

The  draught-pipes  are  of  cast-iron,  and  are  about  J  inch 
thick  and  about  4 \  feet  long,  with  a  clear  diameter  of  2  inches. 

FIG.  21. 


They  are  placed,  strongly  inclined,  over  the  flues  of  a  heating- 
apparatus  and  covered  above  by  a  double  course  of  stone.  The 
air  in  the  iron  draught-pipes,  being  heated  by  the  escaping 
gases  of  combustion,  ascends  and  effects  the  passage  of  a  cur- 
rent of  air  from  above  to  below  in  the  generators.  For  keep- 
ing up  a  constant  ventilation  it  is  claimed  to  be  sufficient  to 
heat  the  furnace  only  once  a  day.  With  this  construction  it 
is  necessary  to  have  as  many  draught-pipes  as  there  are  gener- 
ators. The  same  effect  might,  however,  also  be  attained  by 
connecting  the  pipes  leading  from  several  generators  with  a 
draught-pipe  of  a  somewhat  greater  diameter  and  length. 


ARTIFICIAL    VENTILATION    OF    VINEGAR    GENERATORS.        65 

It  is  not  difficult  to  prove  that  a  uniform  ventilation  of  the 
generators  cannot  be  obtained  by  the  use  of  this  construction. 
As  long  as  the  draught-pipes  are  strongly  heated,  a  very  rapid 
current  of  air  will  pass  through  them  and  the  generators  con- 
nected with  them,  which  will,  however,  decrease  in  the  same 
degree  as  the  pipes  cool  off.  Hence,  in  the  first  case,  a  too 
rapid  current  of  air,  accompanied  by  a  correspondingly  strong 
evaporation  of  alcohol,  would  pass  through  the  generators,  and 
in  the  latter,  ventilation  would  be  so  sluggish  that  the  process 
of  the  formation  of  vinegar  would  not  proceed  in  a  normal 
manner. 

Generators  with  Constant  Ventilation  and  Condensation. — The 
object  to  be  attained  by  the  use  of  special  ventilating  contriv- 
ances is  a  double  one :  To  conduct  a  constant  current  of  air 
through  the  generators,  and,  further,  not  to  allow  the  tem- 
perature to  rise  above  a  certain  limit,  so  as  to  decrease  by 
these  means  the  loss  by  evaporation  of  alcohol  and  acetic  acid. 
This  object  can,  however,  be  attained  only  by  the  use  of  an 
apparatus  which  allows  of  the  most  accurate  regulation  of  the 
current  of  air  passing  through  the  generator,  and  is  connected 
with  a  contrivance  by  which  the  vapors  of  alcohol  and  acetic 
acid  carried  along  by  the  current  of  air  can  be  condensed  as 
much  as  possible.  The  apparatus  described  below  is  well 
adapted  for  the  purpose.  Its  principal  parts  consist  of  the 
generator,  the  apparatus  for  condensing  the  vapors,  and  the 
ventilator. 

The  construction  of  the  lower  part  of  the  generator,  Fig.  22, 
is  the  same  as  of  those  previously  described.  The  cover  fits 
tightly  upon  the  upper  edge  of  the  vat,  the  joint  being  made 
air-tight  by  strips  of  paper  pasted  over  it.  In  the  center  of 
the  cover  is  a  square  aperture,  from  which  rises  a  quadrang- 
ular pyramid,  P,  constructed  of  boards,  upon  which  sits  a  low 
prism,  A.  The  sparger  D  has  its  center  of  motion  upon  the 
strip  L,  placed  in  the  uppermost  portion  of  the  generator,  and 
is  guided  above  in  the  short  strip  Lv  which  carries  the  sharp- 
edged  ring  described  on  page  51.  E  is  the  glass  tube  through 
5 


66 


MANUFACTURE    OF    VINEGAR. 


which  the  alcoholic  liquid  flows  into  the  funnel  of  the  sparger. 
On  the  point  where  the  pyramid  passes  into  the  prism  A,  is  a 
bottom  provided  with  a  circular  aperture,  0,  2J  to  3  inches  in 
diameter.  Upon  the  top  of  the  prism  A  is  placed  a  nut,  in 
which  runs  a  wooden  screw,  provided  on  the  lower  end  with 
a  wooden  disk,  S,  of  a  somewhat  greater  diameter  than  the 
aperture  0.  By  raising  or  lowering  this  screw,  the  aperture 
0  can  be  closed  more  or  less  or  entirely,  and  thus  the  strength 
of  the  current  of  air  regulated  at  will  in  every  generator.  The 
prisms  A  of  all  the  generators  are  connected  with  each  other 
by  the  conduit  R,  constructed  of  boards. 


FIG.  22. 


FIG.  23. 


This  conduit  R  is  connected — best  in  the  center  between 
an  equally  large  number  of  generators — with  the  condensing 
apparatus,  the  chief  feature  of  which  is  a  worm  similar  to 
that  used  in  a  still.  Fig.  24  shows  the  apparatus  in  cross- 
section. 

In  a  sheet-iron  vessel  of  the  same  height  as  the  generator  is 
placed  another  vessel,  so  that  there  is  a  distance  of  about  5} 
inches  between  the  walls.  From  a  reservoir  situated  at  a 
higher  level  cold  water  runs  into  the  apparatus  through  the 
pipe  K,  and  off  through  the  short  pipe  W.  In  the  space  be- 
tween the  walls  of  the  two  vessels  lies  a  tin  coil  with  very  thin 


ARTIFICIAL    VENTILATION    OF    VINEGAR    GENERATORS.        67 

walls  and  a  diameter  of  at  least  2J  inches.  On  top  this  tin 
coil  is  connected  with  the  wooden  tube  R  (Fig.  23)  and  below 
with  the  iron  pipe  R±,  which  leads  to  the  ventilating  appa- 
ratus. C  is  a  glass  tube  about  16  inches  long  and  J  to  f  inch 

FIG.  24. 


in  diameter,  which  reaches  nearly  to  the  bottom  of  the  flask 
half  filled  with  water. 

The  ventilating  apparatus  consists  of  an  ordinary  self-feeding 
stove,  but  its  jacket  is  closed  below  so  that  air  can  only  pass  in 
between  the  heating  cylinder  and  the  jacket  through  the  pipe 
Rl  coming  from  the  condensing  apparatus. 

The  apparatus  works  as  follows :  According  as  combustion 
in  the  stove  proceeds  slowly  or  quickly  by  the  corresponding 
position  of  the  regulating  register,  the  air  between  the  heating 


68  MANUFACTURE    OF    VINEGAR. 

cylinder  and  the  jacket  becomes  less  or  more  heated  and  as- 
cends with  corresponding  velocity.  But  as  the  further  entrance 
of  air  can  take  place  only  through  the  pipe  Rly  the  tin  coil,  and 
the  wooden  tube  R,  a  uniform  current  of  air  from  below  to 
above  must  pass  through  all  the  generators.  To  regulate  the 
strength  of  the  current  for  each  generator,  it  is  only  necessary 
to  close  the  aperture  0  (Fig.  22)  more  or  less  by  raising  or 
lowering  the  screw. 

The  current  of  air  passing  from  the  wooden  tube  R  into  the 
tin  coil  carries  with  it  the  total  amount  of  evaporated  alcohol 
or  acetic  acid.  By  passing  through  the  tin  coil,  which  is  cooled 
by  the  water,  the  air  itself  becomes  cooled  off,  and  the  greater 
portion  of  the  vapors  held  by  it  condense  to  liquid  and  run  off 
through  the  tube  C  into  the  bottle.  The  fluid  thus  obtained 
consists  chiefly  of  alcohol,  water,  and  acetic  acid,  and  is  again 
used  for  the  preparation  of  alcoholic  liquid.  On  account  of  the 
peculiar  form  of  the  cooling  vessel  but  little  water  is  required 
for  feeding  it.  As  the  quantity  of  vapor  separated  from  the  air 
will,  however,  be  the  greater  the  more  energetically  the  tin  coil 
is  cooled  off,  it  is  recommended  to  reduce  the  temperature  of 
the  water  to  nearly  32°  F.  by  throwing  in  pieces  of  ice. 

It  has  been  proposed  to  regain  the  vapors  by  conducting  the 
air  containing  them  into  a  large  vessel  in  which  water  in  the 
form  of  a  fine  spray  trickles  down  or  is  injected.  It  is,  of 
course,  possible  in  this  manner  to  condense  the  greater  portion 
of  vapors  of  a  higher  temperature  and  tension,  but  with  vapors 
of  at  the  utmost  95°  F.  little  success  would  be  attained.  The 
greater  portion  of  the  vapors  remaining  uncondensed,  a  very 
large  quantity  of  fluid  containing  but  little  alcohol  would  be 
obtained  in  the  course  of  a  day,  and  this  fluid  could  at  the  best 
be  used  only  instead  of  water  for  the  preparation  of  alcoholic 
liquid.  The  value  of  the  material  thus  regained  would  not 
cover  the  working  expenses  of  the  apparatus.  By  working, 
however,  with  the  condensing  apparatus  described  above,  the 
condensed  alcohol  does  not  even  contain  the  total  quantity  of 
water  evaporated  with  it,  and  it  need  only  be  compounded 


ARTIFICIAL    VENTILATION    OF    VINEGAR    GENERATORS.        69 

with  the  corresponding  quantity  of  water  and  vinegar  again 
to  yield  alcoholic  liquid. 

The  generator  manufactured  by  Singer,  of  Berlin,  shows  an 
essential  difference  in  construction  from  those  previously  de- 
scribed. It  consists  of  several  shallow  wooden  vessels  arranged 
one  above  the  other  and  connected  with  each  other  by  wooden 

FIG.  25. 


tubes  so  that  the  alcoholic  fluid  runs  drop  by  drop  from  one 
vessel  into  the  other,  passing  thereby  through  the  tubes.  In 
order  to  distribute  the  fluid  as  much  as  possible,  the  tubes  are 
inside  provided  with  horizontal  gutters,  whereby  the  surface  of 
the  fluid  passing  through  is  greatly  increased.  In  addition, 


70 


MANUFACTURE    OF    VINEGAR. 


FIG.  26. 


each  of  the  tubes  is  provided  in  the  center  with  a  slit  running 
length-wise,  allowing  of  a  free  passage  of  the  air.  The  latter 
encounters  in  the  tubes  the  finely-divided  fluid  and  effects  the 
oxidation  of  the  alcohol  to  vinegar.  This  is  repeated  four 
times  and  oftener  before  the  alcoholic  fluid  has  passed  through 
the  apparatus,  whereby,  it  is  claimed,  a  very  complete  forma- 
tion of  vinegar  is  attained.  The  entire  apparatus  stands  in  a 
case  which  protects  it  from  cooling  off  and  from  too  great  an 
access  of  air,  and  which  can  be  heated  in  winter. 

Fig.  25  shows  Singer's  generator  in  cross  section,  and  Fig. 
26  the  separate  vessels  and  their  connection  by  drip  tubes. 
Fig.  25  represents  five  shallow  vats  standing  one  above  the 

other,  at  uniform  distances,  the 
latter  being  effected  by  elongated 
staves. 

In  the  bottoms  of  the  vats  A 
and  A1  are  inserted  37  tubes,  a,  b, 
by  which  they  are  connected  with 
the  vats  B  and  B1  below.  The 
bottoms  of  the  latter  are  provided 
only  with  32  tubes,  which  above 
connect  the  vat  B  with  A1  and 
below  pass  into  the  vat  C. 

As  will  be  seen  from  Fig.  26, 
the  sections  of  the  tubes  through 
which  the  alcoholic  fluid  is  to  run 
slowly  are  provided  above  with 
six  annular  gutters.  Above  these 
gutters  are  four  apertures  for  the 

entrance  of  the  alcoholic  fluid.  In  the  center  the  tubes  are 
slit  lengthwise  for  the  free  admission  of  air.  The  lower  end  of 
each  tube  is  also  provided  with  two  gutters.  On  top  each  tube 
is  closed  with  a  lid,  but  the  end  entering  the  vat  below  is  open. 
Of  all  the  five  vats  only  the  upper  one,  A,  is  provided  with 
a  cover,  and  upon  the  latter  is  fixed  a  holder,  /,  for  securing 
the  tube  g.  Above,  the  latter  is  connected  with  the  reservoir 


ARTIFICIAL    VENTILATION    OF    VINEGAR    GENERATORS.        71 

E,  filled  with  alcoholic  fluid  and  below  ends  in  the  short  pipe 
h,  which  permits  the  alcoholic  fluid  to  run  into  the  upper  vat 
A.  In  addition  to  the  drip-tubes,  every  two  vats  standing  one 
above  the  other  are  connected  with  a  knee. ,  The  upper  one 
of  these  knees  i  issues  from  the  bottom  of  the  vat  A  and  enters 
the  vat  B  close  to  the  bottom.  The  second  tube  connects  in 
the  same  manner,  B  with  J.1,  the  third,  A1  with  B1,  and 
lowest  one,  B1  with  C.  Each  of  these  tubes  is  provided  with 
a  cock  to  allow  of  the  separate  vats  being  connected  or  discon- 
nected at  will.  The  lowest  vat,  (7,  is  provided  with  two  dis- 
charge pipes,  one,  i,  at  the  bottom,  and  the  other,  k,  about  1J 
inches  higher  up. 

The  five  vats  rest  upon  the  reservoir,  D,  which  serves  for 
the  reception  of  the  total  quantity  of  alcoholic  liquid  which 
has  passed  through  the  apparatus.  It  is  provided  with  the 
opening,  #,  which  is  connected  by  a  rubber  tube  with  the 
cock,  J,  on  C.  In  addition,  D,  is  provided  with  a  glass  gauge, 
PJ  which  by  turning  it  downward,  serves  for  discharging  the 
fluid  from  D. 

The  case  enclosing  the  apparatus  is  constructed  of  wood  and 
glass,  the  rubber  tube,  g,  passing  through  the  roof  of  the  reser- 
voir E,  holding  the  alcoholic  fluid.  On  top  the  roof  is  pro- 
vided with  a  trap,  m,  which  can  be  opened  and  closed  at  will 
by  means  of  a  rope.  Below  the  case  is  provided  with  slides 
n  n.  By  opening  the  slides  and  the  trap,  the  admission  of  air 
can  be  regulated. 

In  the  commencement  of  the  operation  the  cock  on  E  is 
opened  and  the  alcoholic  fluid  is  allowed  to  run  through  the 
tube  g,  and  the  short  pipe  h,  until  it  stands  1 J  to  2J  inches 
deep  over  the  drip-tubes.  The  cock  on  the  pipe  i  is  then 
closed.  The  alcoholic  fluid  now  penetrates  into  the  drip-tubes, 
and  runs  through  them  into  B,  which  is  soon  filled  so  far  that 
the  openings  of  the  drip-tubes  are  reached  by  the  level  of 
the  fluid.  As  the  admission  of  alcoholic  fluid  continues  un- 
interruptedly, one  vat  after  another  is  filled,  and  the  alcoholic 
fluid  is  in  the  separate  drip  tubes  distributed  over  a  compara- 


72  MANUFACTURE    OF    VINEGAR. 

tively  very  large  surface,  being  at  the  same  time  brought  in 
intimate  contact  with  fresh  air. 

The  admission  of  alcoholic  fluid  can  readily  be  regulated, 
so  that  on  reaching  the  lowest  vat  it  is  converted  into  vinegar. 

When  the  apparatus  is  once  in  operation,  the  formation  of 
vinegar  progresses  without  interruption,  it  being  only  neces- 
sary regularly  to  fill  the  reservoir  with  fresh  alcoholic  fluid, 
and  to  draw  off  the  finished  vinegar  into  barrels.  If  for  some 
reason  the  operation  is  to  be  interrupted,  the  alcoholic  fluid 
still  contained  in  the  vats  is  drawn  off  through  the  respective 
knees,  and  the  apparatus  is  filled  with  water  to  prevent  dry- 
ing out.  When  manufacture  is  to  be  recommenced,  the  water 
is  drawn  off,  and  alcoholic  fluid  admitted. 

It  is  doubtful  whether  this  apparatus  possesses  advantages 
over  the  ordinary  generator,  since  the  surface  over  which 
the  alcoholic  fluid  is  distributed  is  much  smaller  than  in  gen- 
erators filled  with  shavings. 

Michaelis'  revolving  generator  consists  essentially  of  a  strong 
barrel,  3  feet  3  inches  in  diameter  at  the  widest  point,  and  a 
space  of  3  feet  3  inches  between  the  two  bottoms.  The  barrel 
rests  horizontally  upon  two  supports,  so  that  it  can  be  rolled  to 
and  fro  upon  them.  The  interior  of  the  barrel  is  divided  by  a 
horizontal  lath-grating  into  two  partitions,  .the  upper  smaller 
one  being  filled  with  shavings.  Below  the  lath-grating  in  the 
bottom  of  the  barrel  is  a  horizontal  tube  for  the  admission  of 
air,  and  above  in  the  side  of  the  barrel  a  cock  for  its  escape. 
The  alcoholic  fluid  is  poured  in  close  to  the  lath-grating  by 
means  of  a  funnel,  the  air-cock  is  closed  and  the  barrel  re- 
volved to  allow  of  the  shavings  to  become  thoroughly  saturated 
with  the  alcoholic  liquid.  In  about  15  minutes  the  barrel  is 
brought  back  to  its  original  position,  and  the  air-cock  opened. 
The  commencement  of  the  formation  of  vinegar  will  soon  be 
recognized  by  the  increase  of  temperature  in  the  shavings, 
and  the  operation  is  then  in  full  progress. 

For  the  constant  continuation  of  the  formation  of  vinegar,  it 
is  only  necessary  to  revolve  the  barrel  for  a  few  moments  sev- 


AUTOMATIC    VINEGAR    APPARATUS.  73 

eral  times  a  day  to  saturate  the  shavings  with  the  alcoholic 
fluid.  The  progress  of  the  formation  of  vinegar  is  shown  by 
a  thermometer  placed  in  the  bottom  of  the  upper  space,  the 
lowering  of  the  temperature  indicating  the  completion  of  the 
process. 

The  apparatus  is  cleaned  by  rinsing  the  shavings,  without 
taking  them  from  the  barrel,  with  hot  water,  and  filling  the 
barrel  with  strong  vinegar,  which  is  drawn  off  in  24  hours. 

The  advantages  of  this  generator  consist,  according  to  the 
inventor,  in  cheapness  of  first  cost,  simple  operation,  larger 
yield,  saving  of  alcohol,  and  better  quality  of  the  product. 


CHAPTER  IX. 

AUTOMATIC    VINEGAR    APPARATUS. 

THE  principal  work  to  be  performed  in  a  vinegar  factory 
consists  in  pouring  at  stated  intervals  the  alcoholic  fluid  into 
the  generators.  In  a  large  factory  several  workmen  are  con- 
stantly engaged  in  this  work,  and  losses  by  spilling  are  un- 
avoidable. Further,  it  is  almost  next  to  impossible  always  to 
pour  in  the  same  quantity  at  exactly  the  same  intervals,  and 
sometimes  a  generator  may  even  be  entirely  overlooked,  and 
thus  remain  inactive  until  the  next  supply  of  alcoholic  liquid 
is  poured  in. 

The  greatest  disadvantage  is,  however,  the  interruption  for 
several  hours  daily,  of  the  formation  of  vinegar  in  all  the  gen- 
erators, so  that,  for  instance,  in  a  factory  working  16  hours  a 
day,  one-third  of  the  time  is  lost.  Independently  of  the  small 
return  on  the  capital  invested,  these  interruptions  are  accom- 
panied by  many  other  conditions  injurious  to  the  regular  run- 
ning of  the  factory. 

The  greatest  of  these  evils  is  that  with  the  cessation  of  the 
supply  of  alcoholic  fluid  the  propagation  of  the  vinegar  fer- 


74  MANUFACTURE    OF    VINEGAR. 

ment  diminishes  and  finally  ceases  altogether.  Further,  the 
development  of  heat  in  the  interior  of  the  apparatus  at  the 
same  time  ceases  and  the  temperature  is  reduced  several  de- 
grees, this  phenomenon  appearing  even  in  factories  provided 
with  the  best  heating  apparatus  and  keeping  up  a  constant 
temperature  in  the  workroom  during  the  night. 

In  the  morning  when  work  is  resumed,  it  is  in  most  cases 
necessary  to  vigorously  air  the  apparatus  by  opening  all  the 
•draught  holes,  in  order  to  gradually  restore  the  temperature 
to  the  required  degree,  and  it  will  be  some  time  before  the 
apparatus  again  works  in  a  normal  manner. 

The  vinegar  ferment,  however,  is  very  sensitive  to  changes 
of  temperature,  as  well  as  to  the  concentration  of  the  nourish- 
ing substances  surrounding  it,  and  there  can  be  no  doubt  that 
its  propagation  is  prejudiced  by  the  continuous  variations  of 
temperature  to  which  it  is  exposed  during  the  interruptions  of 
several  hours  a  day.  That  such  is  actually  the  case  is  shown 
by  the  fact  that  the  quantity  of  vinegar  ferment  formed  in  the 
generators  is  small  as  compared  with  that  which,  under  con- 
ditions favorable  to  the  ferment,  forms  in  a  short  time  upon 
alcoholic  liquids. 

Besides  the  debilitation  of  the  vinegar  ferment  and  the  con- 
sequent disturbance  in  the  regular  working  of  the  factory,  the 
repeated  reduction  of  the  temperature  in  the  generators  has  the 
further  disadvantage  that,  besides  the  vinegar  ferment,  other  fer- 
ments for  whose  development  a  low  temperature  is  more  favor- 
able may  be  formed,  and  these  ferments  may  increase  to  such 
an  extent  as  to  entirely  suppress  the  vinegar  ferment.  There 
can  scarcely  be  a  doubt  that  the  many  apparently  inexplicable 
disturbances  in  the  working  of  the  generators,  such  as  their 
remaining  cool  notwithstanding  an  increased  current  of  air, 
the  vinegar  becoming  suddenly  weaker,  or  the  entire  cessation 
of  its  formation,  find  their  easy  explanation  in  the  daily 
interruptions  lasting  for  hours  in  the  regular  working  of  the 
factory. 

Besides  the  increase  in  the  capacity  of  the  factory,  disturb- 


AUTOMATIC    VINEGAR    APPARATUS.  75 

ances  are,  therefore,  less  likely  to  occur  where  the  work  is 
carried  on  uninterruptedly,  but  in  order  to  do  this  there  must 
also  be  a  corresponding  increase  in  the  number  of  workmen 
employed  in  pouring  alcoholic  liquid  into  the  generators. 

By  the  use  of  simple  automatic  contrivances  for  the  regular 
pouring  out  of  the  alcoholic  liquid,  the  number  of  workmen 
employed  in  a  vinegar  factory  can,  however,  be  reduced  to  the 
attendance  required  for  looking  after  the  heating  apparatus, 
raising  the  alcoholic  liquid  to  a  certain  height,  and  an  occa- 
sional control  of  the  temperature  in  the  interior  of  the  genera- 
tors. A  factor}^  thus  arranged  requires  but  little  attendance, 
as  when  once  in  good  working  order  it  may  be  left  to  itself  for 
many  hours  without  the  occurrence  of  any  disturbance. 

According  to  the  characteristics  which  distinguish  the  differ- 
ent constructions  of  continuously  working  apparatus  from  each 
other,  they  may  be  divided  into  two  principal  systems,  viz., 
into  those  with  an  uninterrupted,  and  those  with  a  periodical, 
pouring  out  of  the  alcoholic  liquid,  but  in  either  case  the  latter 
has  to  be  brought  into  a  reservoir  placed  at  a  certain  height 
above  the  generators. 

CONTINUOUSLY    ACTING    APPARATUS. 

The  Terrace  System. — The  alcoholic  liquid,  as  is  well  known, 
cannot  be  converted  into  finished  vinegar  by  passing  once 
through  the  generator,  a  repeated  pouring  into  several,  gen- 
erally three,  different  generators  being  required.  To  avoid 
the  necessity  of  raising  the  alcoholic  liquid  three  times,  three 
rows  of  generators  have  been  arranged  one  above  another,  so 
that"  the  alcoholic  liquid  coming  from  a  reservoir  placed  at  a 
higher  level  flows  first  into  the  uppermost  generator,  and  pass- 
ing through  this,  runs  directly  into  the  second,  and  from 
there  into  the  third,  which  it  leaves  as  finished  vinegar.  Fig. 
27  shows  a  vinegar  factory  arranged  according  to  this  system, 
/.  II,  III,  representing  the  three  rows  of  generators  placed  one 
above  another,  V1  the  reservoir  for  the  alcoholic  liquid,  P  the 
arrangement  for  pumping  the  alcoholic  liquid  into  the  reser- 


76 


MANUFACTURE    OF    VINEGAR. 


voir,  V  the  distributing  vessel  for  the  alcoholic  liquid,  8  the 
collecting  vessel  for  the  finished  vinegar,  .fiTthe  heating  appa- 
ratus for  the  entire  establishment. 

For  a  uniform  supply  of  alcoholic  liquid  to  the  generators 


FIG.  27. 


standing  on  the  same  level  a  conduit,  L,  from  which  the  alco- 
holic liquid  flows  into  each  generator,  runs  above  the  upper- 
most row.  Another  conduit,  Ll,  common  to  all  the  genera- 
tors, serves  for  the  reception  of  fluid  (finished  vinegar)  running 
off  from  the  lowest  row,  and  conducts  it  to  the  collecting  ves- 


AUTOMATIC    VINEGAR    APPARATUS.  77 

sel,  S.  The  arrows  indicate  the  course  the  alcoholic  liquid 
has  to  traverse. 

From  all  appearances  the  arrangement  of  a  factory  according 
to  the  above-described  system  would  be  most  advisable,  there 
being  actually  nothing  to  do  but  to  raise  the  alcoholic  liquid 
once  and  to  remove  the  finished  vinegar  from  the  collecting 
vessel.  In  practice,  however,  this  so-called  terrace  system  pre- 
sents many  difficulties  not  easily  overcome,  the  greatest  un- 
doubtedly being  the  solution  of  the  heating  problem.  Experi- 
ence shows  that  the  temperature  in  a  generator  must  be  the 
higher  the  more  acetic  acid  the  alcoholic  liquid  contains. 
According  to  this,  the  highest  temperature  should  prevail  in 
the  lowest  series  of  generators  (///,  Fig.  27)  and  the  lowest  in 
the  uppermost  (/). 

But  in  practice  just  the  reverse  is  the  case  even  with  the 
use  of  the  best  heating  apparatus,  the  highest  temperature 
prevailing  in  I  and  the  lowest  in  III,  as,  according  to  natural 
law,  the  warm  air  being  specifically  lighter  than  the  cold 
constantly  strives  to  ascend. 

To  overcome  this  drawback  nothing  can  be  done  but  to  place 
the  series  J,  //  and  III  of  the  generators  in  as  many  different 
stories  entirely  separated  from  each  other,  or,  in  case  there  is  a 
central  heating  apparatus  in  the  cellar,  to  correctly  distribute 
the  warm  air  in  the  separate  stories  by  suitably  arranged  reg- 
isters. The  solution  of  this  problem  offers  no  insuperable 
difficulties,  but  requires  the  arrangement  of  the  entire  factory 
to  be  carefully  planned  in  accordance  with  the  laws  of  physics. 

An  unavoidable  drawback  of  the  terrace  system  is  the  cost- 
liness of  the  factory  building,  and,  finally,  that  a  disturbance 
occurring  in  one  of  the  generators  must  simultaneously  affect 
two  others  of  the  vertical  series,  which  must  necessarily  remain 
idle  until  the  disturbance  is  removed.  Considering  all  the 
disadvantages  connected  with  the  terrace  system,  though  it  is 
seemingly  so  suitable,  it  is  but  little  adapted  to  practice,  it 
being  much  preferable  to  place  all  the  generators  on  the  same 
level  and  to  divide  them  into  three  groups,  each  of  which  is 


78  MANUFACTURE    OF    VINEGAR. 

provided  with  a  reservoir  for  the  alcoholic  liquid  and  a  col- 
lecting vessel. 

The  mode  of  working  according  to  this  system  is  as  follows : 
The  alcoholic  liquid  is  pumped  into  a  reservoir,  from  which  it 
passes  through  group  /  of  generators  and  collects  in  a  vessel. 
From  the  latter  it  is  pumped  into  a  second  reservoir  placed  on 
the  same  level  with  the  first,  and  runs  through  group  II  of 
generators  into  another  collecting  vessel ;  from  there  it  is  again 
pumped  into  a  third  reservoir,  and  after  passing  through  group 
/// of  generators  finally  collects  as  finished  vinegar  in  a  third 
collecting  vessel. 

Though  the  arrangement  of  all  the  generators  on  the  same 
level  renders  it  necessary  to  raise  the  alcoholic  liquid  three 
times,  it  would  seem  more  suitable  than  the  terrace  system  for 
the  following  reasons:  1.  By  a  suitable  regulation  of  the  heat- 
ing apparatus  the  required  temperature  can  be  readily  main- 
tained in  the  separate  groups  of  generators.  2.  In  case  of  a 
disturbance  in  one  of  the  groups,  the  generator  in  question  can 
be  left  out  without  causing  an  interruption  in  the  work  of  the 
other  groups.  3.  The  power  required  to  pump  the  alcoholic 
liquid  three  times  into  the  reservoirs  Vl,  V2,  and  F3,  is  not 
much  greater  than  that  which  has  to  be  used  to  raise  it  to  the 
height  of  the  reservoir  in  factories  arranged  according  to  the 
terrace  system.  4.  Notwithstanding  the  greater  area  required, 
the  erection  of  a  one-story  factory  is  less  expensive  than  that 
of  a  three-story  building  with  complicated  heating  apparatus 
and  very  strong,  solid  floors,  which  are  required  on  account  of 
the  great  weight  of  the  generators. 

The  uniform  distribution  of  the  alcoholic  liquid  into  each 
generator  is  very  simple  in  factories  arranged  according  to  the 
terrace  system,  and  can  be  effected  in  the  following  manner  : 

The  false  heads  are  fitted  water-tight  in  the  generators ; 
they  are  provided  either  with  narrow  holes  alone,  or  with  aper- 
tures loosely  filled  with  cotton-wick,  pack-thread,  etc.  The 
pipes  ascending  from  the  vinegar-forming  space,  which  is  filled 
with  shavings,  are  inserted  water-tight  in  the  false  bottoms. 


AUTOMATIC    VINEGAR    APPARATUS. 

On  the  reservoir  containing  the  alcoholic  liquid  is  a  spigot 
which  can  be  accurately  adjusted,  and  is  securely  connected 
with  the  conduit  leading  to  the  separate  generators.  At  the 
place  on  the  conduit  where  the  alcoholic  liquid  is  to  be  intro- 
duced into  the  generator  is  a  discharge-pipe  also  provided  with 
a  spigot. 

When  the  factory  is  to  be  put  in  operation  the  reservoir  is 
first  filled  with  alcoholic  liquid,  the  spigots  on  the  several  gen- 
erators being  entirely  open,  but  the  principal  spigot  closed. 
Now,  by  suddenly  opening  the  latter,  the  air  in  the  conduit  i& 
expelled  by  the  alcoholic  liquid  flowing  in,  and  the  latter 
rushes  in  a  full  stream  from  the  spigots  connecting  the  conduit 
with  the  generators.  These  spigots  are  then  closed  so  far  that 
only  the  quantity  of  alcoholic  liquid  required  for  the  regular 
process  of  the  formation  of  vinegar  can  enter  the  generators. 
To  prevent  the  force  of  pressure  from  varying  too  much  in  the 
conduit  by  the  lowering  of  the  level  of  the  fluid  in  tire  reser- 
voir, it  is  recommended  to  give  the  latter  only  a  slight  height 
but  a  large  bottom  surface. 

From  the  lower  portion  of  the  uppermost  series  of  genera- 
tors the  alcoholic  fluid  then  gradually  reaches  through  a  pipe 
the  false  bottoms  of  the  next  series,  and  from  this  the  lowest 
series,  from  which  it  runs  off  as  finished  vinegar  into  the  col- 
lecting vessel. 

It  will  readily  be  seen  that  some  time  for  experimenting  is 
required  before  a  factory  arranged  according  to  this  system 
can  be  brought  into  regular  working  order,  it  being  necessary 
to  test  the  fluids  running  off  from  the  different  groups  of  gen- 
erators as  to  their  contents  of  acetic  acid  in  order  to  find  out 
whether  too  much  or  too  little  or  just  enough  alcoholic  liquid 
reaches  the  generator,  so  that  the  liquid  running  off  from  the 
lowest  series  contains  no  alcohol  and  may  be  considered  a& 
finished  vinegar.  Any  fault  in  the  working  of  the  generators 
can  in  this  case  be  overcome  by  a  corresponding  adjustment 
of  the  spigots  so  as  to  regulate  the  influx  of  alcoholic  liquid. 

Theoretically   no  more   simple  or  convenient   process  for 


80'  MANUFACTURE    OF    VINEGAR. 

making  vinegar  than  the  terrace  system  could  be  devised. 
Provided  the  spigots  supplying  the  separate  generators  be  once 
correctly  adjusted  and  the  temperature  of  the  different  stories 
suitably  regulated,  it  is  only  necessary  constantly  to  supply 
the  reservoir  with  alcoholic  liquid,  and  the  heating  apparatus 
with  fuel,  in  order  to  carry  on  the  work  for  any  length  of 
time  desired.  The  disadvantages  connected  with  this  system 
having  been  already  explained  need  not  be  further  referred  to. 

Lcnze's  chamber  generator  :  *  This  apparatus  is  a  Schuetzen- 
bach  generator  of  logically  improved  construction,  and  not,  as 
might  be  supposed  at  the  first  glance,  an  arbitrary  modifica- 
tion of  the  exterior  shape.  Its  construction  is  based  upon  the 
following  principles : 

1.  Saving  of  space  and  volume.  2.  Simplification  of  the 
work  and  facility  of  control.  3.  Utilization  to  the  best  ad- 
vantage of  the  square  fermentation-surface.  4.  The  process  is 
carried  on  without  being  separated  by  partitions  in  many  iso- 
lated narrow  columns  of  shavings.  5.  Surface-fermentation 
with  little  height.  6.  Large  producing  capacity. 

The  average  height  of  the  apparatus  is  about  7  feet.  It  is 
rectangular  in  form,  is  built  entirely  of  wood,  no  hoops  what- 
ever being  used,  and  is  of  solid  and  massive  construction.  It 
is  made  in  three  sizes.  Fig.  28  shows  a  No.  3  apparatus  with 
a  base  of  about  107  square  feet,  length  10  feet,  width  6  feet, 
and  a  capacity  of  producing  20  to  25  quarts  of  13  per  cent, 
vinegar  per  10J  square  feet  of  shavings-surface  (base  of  gen- 
erator). 

The  alcoholic  liquid  is  periodically  supplied  at  fixed  inter- 
vals, but  the  operation  may  also  be  carried  on  continuously 
day  and  night. 

The  attendance  of  the  apparatus  is  entirely  mechanical,  by 
means  of  a  pump  operated  by  hand  or  power.  Losses  of 
material  by  spilling  or  otherwise  are  impossible  since  the 
alcoholic  liquid  moves  in  closed  tin  pipes  and  the  finished 
vinegar  is  conveyed  in  the  same  manner. 

*.J.  Lenze,  Iserlohn,  Westfalen,  Germany. 


AUTOMATIC    VINEGAR    APPARATUS, 


81 


The  apparatus  is  furnished  with  a  lath-bottom  and  a  per- 
forated head,  the  intermediate  space  being  packed  with  beech 
shavings.  The  air-holes  are  between  the  actual  bottom  and 
the  lath-bottom  and  the  air-outlets  below  the  perforated  head. 
The  alcoholic  liquid  is  very  uniformly  distributed  over  the 
entire  large  surface  of  shavings  by  the  perforated  head.  The 
latter  is  tightly  covered  with  cloth,  divided  into  square  fields, 

FIG.  28. 


and  so  secured  that  it  cannot  warp  or  get  out  of  position. 
Notwithstanding  its  large  superficial  area  the  perforated  head 
is  the  coolest  place  in  the  apparatus  and  this  evidently  con- 
tributes towards  reducing  the  loss  by  evaporation  to  a  mini- 
mum, and  such  loss  can  be  still  further  limited  by  the  use  of 
a  cover  fitting  almost  air-tight.  The  upper  layer  of  shavings 
is  also  not  impaired  by  higher  degrees  of  heat,  because  the  as- 
cending air  which  has  been  heated  and  exhausted,  is  con- 
6 


82  MANUFACTURE    OF    VINEGAR. 

stantly  cooled  by  the  pourings  of  alcoholic  liquid  and  partly 
condenses  on  the  lower  surface  of  the  perforated  head,  and 
thus  cooled,  escapes  through  a  pipe-system  below  the  perforated 
head. 

The  mode  of  operating  such  an  apparatus  and  its  attend- 
ance is  illustrated  by  Fig.  28. 

The  alcoholic  liquid  is  contained  in  the  vat  C  and  a  suffi- 
cient quantity  of  it  is  by  means  of  the  pump  P  conveyed  to 
the  vat  A,  where  it  is  diluted  to  a  weak  wash.  When  the 
operation  is  carried  on  with  back  pourings,  the  vat  B  contains 
the  vinegar;  otherwise  it  is  omitted.  The  intermediate  vat 
E  effects  automatically  by  suitable  contrivances  the  measuring 
off  of  the  separate  pourings,  so  that  after  pumping  the  entire 
quantity  of  alcoholic  liquid  required  for  one  day,  the  actual 
labor  is  finished,  which  requires  about  one  hour's  consump- 
tion of  time  and  power,  no  matter  whether  one  or  several  ap- 
paratuses are  operated,  larger  pumps  being  used  in  the  latter 
case. 

For  the  accurate  control  of  the  operation  a  contrivance  is 
provided  which  indicates  in  the  office  whether  and  at  what 
time  the  separate  pourings  have  been  effected. 

The  product  running  off  from  the  apparatus  collects  in  the 
course  of  the  day  in  the  vat  D.  When  the  latter  is  full,  the 
overflow  passes  through  a  pipe  to  the  storage-vat.  By  this 
arrangement  the  danger  of  any  of  the  vats  running  over  is 
excluded. 

Plate  Generator. — This  generator,  patented  by  Dr.  Bersch,  of 
Vienna,  Austria,  is  so  arranged  as  to  render  the  formation  of 
aldehyde  as  well  as  the  destruction  of  acetic  acid  already 
formed  impossible,  and  the  loss  by  evaporation  is  reduced  to 
a  minimum.  As  will  be  seen  from  the  description,  the 
arrangement  of  the  apparatus  is  such  that  on  all  portions  of 
the  surface  of  the  plates  air  and  alcoholic  liquid  are  in  undis- 
turbed contact.  Hence  the  formation  of  vinegar  takes  place 
constantly  and  the  regulation  of  the  current  of  air  can  be 
effected  with  the  utmost  accuracv.  Since  the  effective  surface 


AUTOMATIC    VINEGAR    APPARATUS.  83 

of  each  apparatus,  i.  e.,  the  surface  upon  which  the  formation 
of  vinegar  actually  takes  place,  is  more  than  10,764  square 
feet,  the  performance  of  this  generator  is  extremely  large,  sur- 
passing by  far  that  of  a  generator  packed  with  shavings. 

This  generator  is  provided  with  a  contrivance  which  auto- 
matically attends  to  the  pouring-in  of  alcoholic  fluid  with  the 
regularity  of  clock-work,  and  thus  the  work  of  a  factory  using 
a  large  number  of  generators  can  be  done  by  a  single  work- 
man, he  having  nothing  else  to  do  than  to  fill  once  a  day  the 
reservoir  for  alcoholic  fluid. 

In  its  most  recent  construction  the  plate-generator  consists 
of  a  vat  filled  inside  with  layers  of  extremely  thin  plates  of 
wood  arranged  in  such  a  manner  that  the  separate  layers  are 
fixed  crosswise  at  right  angles  one  above  the  other.  Since 
every  two  plates  in  the  layers  lying  alongside  each  other  are 
kept  apart  by  prismatic  wooden  rods,  fluid  can  run  down  on 
both  sides  of  the  plates,  and  air  ascend  undisturbed  between 
them. 

Since  the  total  surface  of  'the  wooden  plates  in  a  generator 
about  8J  feet  high  is  more  than  10764  square  feet,  and  for- 
mation of  vinegar  takes  place  uninterruptedly  upon  this 
entire  surface,  the  efficacy  of  the  plate  generator  as  regards 
producing  capacity  is  the  highest  attainable. 

Through  a  pipe,  open  at  both  ends,  in  the  bottom  of  the 
generator,  air  is  admitted  to  the  interior.  The  upper  portion 
of  this  pipe  is  furnished  with  a  hood  to  prevent  fluid  from 
dropping  into  it,  and  the  lower  opening  is  covered  with  fine 
gauze  to  exclude  the  entrance  of  vinegar  lice  (vinegar  mites). 

The  strength  of  the  current  of  air  in  the  generator  is  regu- 
lated by  a  register-bar  in  the  cover  of  the  apparatus,  in  which 
is  also  fixed  a  thermometer.  In  the  commencement  of  the 
operation  the  register-bar  is  so  set  that  the  thermometer  indi- 
cates the  temperature — about  91°  to  93°  F. — suitable  for  the 
formation  of  vinegar.  So  long  as  alcoholic  liquid  runs  in 
and  the  temperature  of  the  workroom  remains  the  same,  the 
same  temperature  will  be  indicated  by  the  thermometer,  be- 


84 


MANUFACTURE    OF    VINEGAR. 


cause  in  equal  periods  of  time  the  same  quantity  of  vinegar 
will  always  be  formed  and  a  quantity  of  heat  corresponding 
to  it  developed. 

The  uniform  distribution  of  the  alcoholic  fluid  in  the  form 
of  very  fine  drops  over  the  plates  in  the  interior  of  the  gen- 
erator is  effected  by  a  sparger  fixed  over  the  uppermost  layer 
of  plates. 

The  apparatus,  like  every  other  generator,  can  be  charged 
by  pouring  in  the  alcoholic  liquid  by  hand.  However,  to 
make  it  entirely  independent  of  the  workman,  and  especially 


to  keep  it  working  regularly  day  and  night  without  interrup- 
tion, it  is  provided  with  an  automatic  pouring  contrivance. 
This  contrivance  consists  of  a  vat  of  such  a  size  as  to  be  capa- 
ble of  holding  the  fluid  required  for  supplying  for  24  hours 
one  generator  or  a  group  of  two,  three,  four  or  more  genera- 
tors. In  this  supply-vat  floats  in  a  suitable  guide  a  wooden 
float-gauge,|which  rises  and  sinks  with  the  level  of  the  fluid. 
To  this  float-gauge  is  secured  a  siphon,  the  longer  leg  of  which 
is  furnished  with  ^a  [checking  contrivance  which  has  to  be 


AUTOMATIC    VINEGAR    APPARATUS. 


85 


accurately  regulated.  By  shifting  this  checking  contrivance, 
the  quantity  of  fluid  discharged  in  a  certain  unit  of  time,  for 
instance,  in  one  hour,  can  be  determined.  Since  the  siphon 
sinks  with  the  level  of  the  fluid,  and  its  length  remains  un- 
changed, the  fluid  always  runs  off  under  the  same  pressure. 

The  liquid  running  from  the  siphon  passes  into  a  distribut- 
ing vessel  underneath.  The  latter  should  be  of  sufficient 
capacity  to  hold  the  total  quantity  of  liquid  required  for  one 

FIG.  30. 


pouring  upon  all  the  generators  in  a  battery.  If,  for  instance, 
every  generator  in  a  battery  of  twenty-four  is  to  receive  a 
pouring  of  3  quarts,  the  distributing  vessel  should  have  a 
capacity  of  at  least  3  X  24  =  72  quarts.  The  automatic  pour- 
ing contrivance  is  fixed  in  the  distributing  vessel.  When  the 
latter  contains  the  quantity  of  alcoholic  liquid  required  for 
one  pouring  for  a  determined  number  of  generators,  the  time 
fixed  between  every  two  pourings  has  elapsed.  The  auto- 
matic pouring  contrivance  then  opens  the  distributing  vessel 
and  the  alcoholic  liquid  passes  through  the  conduits  to  the 


86  MANUFACTURE    OF    VINEGAR. 

generators.  When  the  distributing  vessel  has  been  emptied, 
the  discharge-contrivance  closes  automatically,  the  distribut- 
ing vessel  is  filled  within  the  determined  time,  and  is  again 
emptied  when  this  time  has  elapsed.  The  automatic  distribut- 
ing contrivance  thus  continues  working  without  interruption 
so  long  as  liquid  is  contained  in  the  supply-vat.  If  the  latter 
is  of  sufficient  capacity  to  hold  enough  alcoholic  liquid  for  24 
hours,  it  is  only  necessary  to  fill  it  in  the  morning. 

Figs.  29  and  30  show  the  arrangement  of  the  separate  parts 
of  a  plant  for  automatically  working  plate  generators.  Fig. 
29  is  a  view  from  above  and  Fig.  30  a  side  view.  V  is  the 
supply-vat  for  the  alcoholic  liquid,  S  the  float-gauge  to  which 
is  secured  the  siphon  H.  A  is  the  automatic. distributor,  and 
J  the  conduits  conveying  the  alcoholic  liquid  to  the  separate 
plate-generators  P.  The  dotted  line  aa  represents  the  level  of 
the  fluid  in  the  supply-vat. 

PERIODICALLY    WORKING    APPARATUS. 

The  Three-group  System. — In  the  second  system  of  automatic 
generators  it  has  been  sought  to  imitate  the  ordinary  working 
of  a  vinegar  factory  by  providing  the  apparatus  with  certain 
mechanical  appliances  which  allow  of  the  distribution  at  cer- 
tain stated  intervals  of  any  desired  quantity  of  alcoholic  liquid 
into  the  generators.  The  term  "  periodical  "  may  be  applied 
to  this  system  of  automatic  apparatus. 

The  mechanical  appliances  used  for  the  purpose  of  admitting 
at  certain  intervals  a  fixed  quantity  of  alcoholic  fluid  into  the 
generator  may  be  constructed  in  various  ways,  the  tilting 
trough,  shown  in  Figs.  12  and  13,  p.  49,  being  an  example. 
By  a  modification  of  the  apparatus,  as  shown  in  Fig.  31,  any 
desired  quantity  of  fluid  can  with  its  assistance  be  at  certain 
intervals  admitted  to  the  generator.  The  fluid  may  be  either 
poured  out  upon  the  false  head,  or,  what  is  more  suitable 
for  its  better  distribution,  used  for  feeding  a  sparger. 

As  seen  from  the  illustration  a  prismatic  box  with  a  bottom 
formed  of  two  slightly  inclined  planes,  stands  at  a  suitable 


AUTOMATIC    VINEGAR    APPARATUS. 


87 


height  over  each  generator.  In  this  box  a  tilting  trough  is 
placed  so  that  its  axis  of  revolution  runs  parallel  with  the  line 
formed  by  the  two  bottom  surfaces  of  the  box.  On  the  point 
of  contact  of  the  two,  a  pipe  is  inserted  which  extends  to  the 
false  head  or  to  the  funnel  of  the  sparger.  Above  the  box  is 
a  spigot  connected  by  a  pipe  with  a  reservoir  for  the  alcoholic 

FIG.  31. 


fluid  placed  at  a  higher  level.  This  reservoir  serves  for  sup- 
plying a  large  number  of  generators,  and  can  be  shut  off  by  a 
carefully  adjusted  spigot.  From  the  latter  a  vertical  pipe 
leads  to  the  conduit  running  in  a  horizontal  direction  over  the 
generators.  The  pipe  is  provided  with  small  spigots  which 
discharge  the  fluid  into  the  tilting  troughs. 


88 


MANUFACTURE    OF    VINEGAR. 


By  giving  each  tilting  trough  such  a  capacity  that,  for  in- 
stance, each  partition  holds  5  quarts,  and  adjusting  the  spigot 
so  that  30  minutes  are  required  for  filling  one  partition,  the 
trough  will,  at  the  expiration  of  this  time,  tilt  over  and  empty 
the  fluid  upon  the  inclined  planes.  From  here  it  runs  into 
the  sparger,  and  setting  the  latter  in  motion  is  poured  in  the 
form  of  a  fine  spray  over  the  shavings.  Since  the  other  parti- 
tion of  the  tilting  trough  has  the  same  capacity,  as  the  first, 
and  the  quantity  of  the  alcoholic  fluid  remains  the  same,  the 

FIG.  32. 


trough  will,  after  the  expiration  of  30  minutes,  again  tilt  over, 
and  again  empty  5  quarts  of  fluid,  this  being  continued  as 
long  as  the  reservoir  contains  any  fluid. 

In  place  of  the  tilting  trough  the  so-called  "  siphon-barrel," 
Fig.  32,  may  be  used  for  effecting  the  discharge  of  a  certain 
quantity  of  fluid  at  a  stated  interval.  In  a  spherical  vessel 
placed  at  a  higher  level  than  the  edge  of  the  funnel  of  the 
sparger  is  a  siphon,  the  longer  leg  of  which  passes  through  the 
bottom  of  the  vessel  into  the  funnel.  On  the  edge  of  the  vessel 


AUTOMATIC    VINEGAR    APPARATUS. 


89 


Fro.  88. 


is  a  spigot  which  is  connected  with  the  pipe  conveying  the 
fluid,  and  so  adjusted  that  within  a  previously  determined  space 
of  time  the  vessel  is  filled  with  fluid  up  to  the  height  indicated 
by  the  dotted  line.  As  soon  as  the  fluid  reaches  that  height, 
action  of  the  siphon  commences,  and  the  content  of  the  vessel 
runs  through  the  longer  leg  into  the  funnel  of  the  sparger  until 
its  level  is  sunk  to  the  edge  of  the  shorter  leg.  The  action  of 
the  siphon  then  ceases  until  the  vessel  is  again  filled  up  to  the 
line,  when  it  recommences,  and  so  on. 

The  siphon  of  bent  glass  tubes  being  very  liable  to  breakage, 
it  is  frequently  replaced  by  the  so-called  bell-siphon,  the  ar- 
rangement of  which  is  shown  in  Fig.  33.  It  consists  of  a  glass 
tube  which  forms  the  longer  leg  of 
the  siphon,  while  a  glass  cylinder 
secured  to  this  tube  by  means  of  a 
perforated  cork,  represents  the  other 
leg.  The  action  of  this  siphon  is 
the  same  as  the  other. 

In  working  with  automatic  appa- 
ratus, fixed  quantities  of  fluid  being 
at  stated  intervals  introduced,  pro- 
vision for  the  reception  of  the  fluid 
must  be  made  in  the  apparatus  itself, 
or  for  its  being  conducted  to  a  spe- 
cial reservoir  at  the  rate  at  which  it 
trickles  from  the  shavings.  In  the 
first  case  the  space  beneath  the  false 
bottom  must  be  of  sufficient  size  to 

receive  the  fluid  passed  through  the  apparatus  in  a  certain 
time.  This  time  being  suitably  fixed  for  12  hours,  the  appa- 
ratus can  during  this  time  work  without  further  attendance, 
so  that  the  required  space  beneath  the  false  bottom  can  be 
calculated  by  multiplying  the  number  of  pourings  with  the 
quantity  of  fluid  poured  in  at  one  time. 

Example : — The  generator  receives  at  intervals  of  30  min- 
utes a  pouring  of  5  quarts,  hence  in  12  hours  24  pourings  of 


90  MANUFACTURE    OF    VINEGAR. 

5  quarts  each  =  120  quarts.  The  space  beneath  the  perfo- 
rated false  bottom  must  therefore  be  of  sufficient  capacity  to 
receive  up  to  the  height  of  the  draught-holes  at  least  120 
quarts  of  fluid. 

As  will  be  seen  from  the  following  general  description  of  a 
vinegar  factory,  arranged  according  to  the  automatic  principle, 
it  is  decidedly  preferable  to  arrange  the  generators  so  that  the 
fluid  trickling  from .  the  shavings  is  at  once  conducted  to  a 
collecting  vessel. 

Arrangement  of  a  Vinegar  Factory  Working  According  to  the 
Automatic  Principle. — As  previously  stated,  it  is  not  possible  to 
convert  all  the  alcohol  contained  in  the  liquid  into  acetic  acid 
by  one  pouring ;  only  a  portion  of  the  alcohol  being  converted, 
and  this  semi-product  is  brought  into  a  second  generator,  and, 
if  the  liquid  used  is  very  rich  in  alcohol,  into  a  third.  In  the 
second  apparatus  another  portion  of  the  alcohol  is  converted 
into  acetic  acid,  and  the  process  finished  in  the  third. 

It  being  in  all  cases  advisable  to  prepare  vinegar  with  a 
high  percentage  of  acetic  acid,  most  manufacturers  now  pass 
the  alcoholic  liquid  successively  through  three  generators.  In 
practice  it  is  recommended  to  place  the  generators  which  are 
to  receive  alcoholic  liquid  of  the  same  content  of  acetic  acid 
alongside  each  other,  which  leads  naturally  to  the  division  of 
the  generators  into  three  groups.  If,  for  instance,  a  factory 
contains  48  generators,  each  group  contains  16  ;  group  I  is 
charged  with  freshly  prepared  alcoholic  liquid  ;  the  generators 
of  group  II  contain  the  alcoholic  liquid  which  has  already 
passed  through  those  of  group  I,  and  group  III  is  charged 
with  the  fluid  yielded  by  group  II. 

Besides  the  easy  control  of  the  work,  this  arrangement  into 
groups  has  another  advantage.  The  generators  in  which  the 
last  remnants  of  the  alcohol  of  a  quite  strong  fluid  are  to  be 
converted  into  acetic  acid  are  best  kept  at  a  somewhat  higher 
temperature  ;  and  with  a  suitably  arranged  heating  apparatus 
and  the  eventual  use  of  curtains  by  which  the  workroom  can 
be  divided  at  will  into  two  or  three  partitions,  it  can  be  readily 


AUTOMATIC    VINEGAR    APPARATUS.  91 

arranged  to  convey  somewhat  more  heat  to  the  second  group 
of  generators  and  the  greatest  quantity  of  it  to  the  third. 

The  height  of  the  actual  workroom  of  the  factory  should  not 
be  greater  than  required  by  that  of  the  generators.  The  reser- 
voir is  placed  under  the  roof  of  the  workroom,  while  the  col- 
lecting vessels  are  either  sunk  in  the  floor  or  placed  in  the 
cellar. 

Below  is  given  a  description  of  a  periodically  working  estab- 
lishment with  24  generators.  The  generators  are  arranged  in 
three  groups,  I,  II,  and  III,  the  following  articles  belonging 
to  each  group  : — 

8  generators ; 

1  reservoir; 

1  collecting  vessel ; 

8  apparatuses  for  the  distribution  of  the  alcoholic  liquid  into 
the  generators ; 

Conduits  for  the  alcoholic  liquid  to  be  poured  in  ; 

Conduits  for  the  alcoholic  liquid  running  off. 

For  the  three  groups  in  common  : — 

A  pump  to  convey  the  alcoholic  liquid  from  the  collecting 
vessels  to  the  reservoirs. 

A  flue  for  the  conveyance  of  warm  air  from  the  heating 
apparatus  in  the  cellar  and  for  its  distribution  in  the  work- 
room. 

An  apparatus  for  heating  the  alcoholic  liquid. 

The  three  reservoirs  rest  upon  the  joists  of  the  ceiling  of  the 
workroom,  each  being  enclosed  by  a  small  chamber  con- 
structed of  boards  which  are  papered.  In  the  floor  of  each 
chamber  is  a  man-hole  for  access  to  the  reservoir.  The  man- 
holes should  not  be  furnished  with  doors,  it  being  of  import- 
ance that  the  reservoirs  should  constantly  be  surrounded  by 
warm  air  which  ascends  through  the  man-holes.  To  prevent 
loss  by  evaporation  the  reservoirs  should  be  provided  with 
well-fitting  covers. 

To  retain  solid  bodies  such  as  shavings,  flakes  of  mother  of 
vinegar,  etc.,  which  might  eventually  obstruct  the  fine  aper- 


92  MANUFACTURE    OF    VINEGAR. 

tures  in  the  false  head  or  sparger,  a  filter  is  placed  on  the 
end  of  the  pipe  through  which  the  alcoholic  liquid  passes  into 
the  reservoirs.  A  suitable  filter  for  the  purpose  is  a  horse-hair 
sieve  containing  a  linen  bag,  the  latter  being  from  time  to 
time  replaced  by  a  new  one. 

The  conduits  for  the  conveyance  of  the  alcoholic  liquid  to 
the  distributing  vessels  and  from  there  to  the  generators  are 
best  constructed  of  thick  glass  tubes,  the  connection  of  two 
pieces  being  effected  by  pieces  of  rubber  hose  pushed  over  the 
ends  and  secured  with  twine. 

Each  generator  may  be  furnished  with  a  vessel  containing  the 
automatic  arrangement,  it  being,  however,  in  this  case  neces- 
sary to  provide  for  each  a  special  conduit  from  the  reservoir, 
which  for  a  factory  containing  a  large  number  of  generators  is 
rather  expensive.  Hence  it  is  recommended  to  use  for  each 
group  only  one  or  at  the  utmost  two  distributing  vessels,  and 
from  them  to  extend  smaller  conduits  to  the  separate  -gene- 
rators. Each  of  the  principal  conduits  is  provided,  at  the  place 
where  it  enters  the  distributing  vessel,  with  a  spigot,  which  is 
adjusted  for  the  discharge  of  a  certain  quantity  of  alcoholic 
liquid.  If,  as  above  mentioned,  every  generator  is  to  receive 
a  pouring  of  5  quarts  of  alcoholic  liquid  every  30  minutes,  the 
distributing  vessel  serving  for  a  group  of  8  generators  must 
have  a  capacity  of  40  quarts,  and  the  spigot  has  to  be  so 
adjusted  that  exactly  this  quantity  passes  through  it  in  30 
minutes. 

The  discharge-pipe  of  the  automatic  arrangement  must  enter 
a  space  in  which  are  inserted  eight  pipes  having  the  same 
diameter,  which  conduct  the  alcoholic  liquid  to  the  separate 
generators.  By  this  arrangement  all  the  generators  receive 
simultaneously  a  pouring  of  an  equal  quantity  of  fluid  which 
either  sets  the  sparger  in  motion  or  gradually  trickles  through 
the  apertures  in  the  false  head.  The  alcoholic  liquid  which 
has  passed  through  the  generators  collects  either  in  the  space 
under  the  false  bottom  or  runs  directly  through  conduits  to 
the  collecting  vessels. 


AUTOMATIC    VINEGAR    APPARATUS.  93 

The  conduits  placed  before  the  discharge  apertures  of  the 
generators  are  intended  to  conduct  the  alcoholic  liquid  to  the 
reservoirs,  and  there  being  no  pressure  of  fluid  in  them  they 
might  be  merely  open  gutters.  For  the  sake  of  cleanliness  and 
to  avoid  losses  by  evaporation  it  is,  however,  advisable  to  use 
glass  tubes  for  the  purpose.  At  the  places  where  the  dis- 
charge-pipes of  the  generators  are  located,  the  connection  of 
two  glass  tubes  is  effected  by  a  wooden  joint  with  an  aperture 
on  top  in  which  is  placed  a  glass  funnel.  For  collecting  ves- 
sels for  the  alcoholic  fluid  running  off  from  the  generators  of 
one  group,  vats  provided  with  lids  are  used.  They  have  to  be 
placed  so  low  that  some  fall  can  be  given  to  the  conduits,  and 
in  each  of  them  is  a  pipe  provided  with  a  spigot,  which  serves 
as  a  suction-pipe  for  the  pump  intended  to  raise  the  alcoholic 
fluid. 

The  manner  of  working  in  a  factory  thus  arranged  is  as 
follows :  *  The  collecting  vessel  Ci  serves  for  the  preparation 
of  the  alcoholic  liquid,  which  is  then  pumped  into  the  reser- 
voir Ri,  from  whence  it  runs  through  the  first  group  of  gen- 
erators, Gi,  to  the  collecting  vessel,  Cn.  From  this  it  is 
pumped  into  Rn,  and  runs  through  the  second  group  of  gen- 
erators, Gn,  into  the  collecting  vessel  Cm.  On  being  pumped 
up  the  third  time  it  runs  from  the  reservoir  Rm  through  the 
third  group  of  generators  Gm,  and  passes  as  finished  vinegar 
either  into  a  fourth  collecting  vessel  or  is  at  once  conducted 
into  storage  barrels. 

The  distance  the  alcoholic  liquid  has  to  be  raised  from  the 
bottom  of  the  collecting  vessels  to  the  reservoir  amounting  to 
not  more  than  from  23  to  25  feet,  an  ordinary  suction-pump 
may  be  used  for  the  purpose,  though  a  forcing  pump  is  better, 
it  doing  the  work  more  rapidly.  The  pump  must  be  con- 
structed of  material  entirely  indifferent  to  acetic  acid  (wood, 
glass,  hard  rubber,  tin,,  or  thickly  silvered  metal). 

*To  avoid  repetition  the  collecting  vessels  are  designated  :  Ci,  n,  in  ;  the  res- 
ervoirs Ri,  iiTand.iii1.;  the  groups  of  generators  Gi,  n,  in. 


94 


MANUFACTURE    OF    VINEGAR. 


Any  metallic  vessels  used  in  the  factory  should  be  of  pure 
tin,  i.  e.,  unalloyed  with  other  metals,  it  being  the  only  metal 
entirely  indifferent  towards  acetic  acid,  but  unfortunately  it  is 
too  soft  to  be  suitable  for  the  construction  of  pumps. 

The  pump  is  generally  located  in  the  immediate  neighbor- 
hood of  the  collecting  vessels,  and  the  three  branches  of  its 
suction  pipe  pass  into  the  latter.  When  one  of  the  collecting 

FIG.  34. 


vessels  is  to  be  emptied,  the  spigot  of  the  branch  pipe  entering 
it  is  opened  and  the  spigots  of  the  other  branch  pipes  are 
closed. 

Ordinary  well  or  river  water  being  used  in  the  preparation 
of  the  alcoholic  liquid,  the  temperature  of  the  latter  does  not 
generally  exceed  54°  F.,  and  if  it  were  thus  introduced  into 
the  generators  acetification  would  be  very  sluggish  until  the 
temperature  rises  to  above  68°  F.  Independently  of  the  loss 


AUTOMATIC    VINEGAR    APPARATUS.  95 

of  time,  there  would  be  the  further  danger  of  injuring  the  de- 
velopment of  the  vinegar  ferment ;  hence  it  is  necessary  to  heat 
the  alcoholic  liquid  to  the  temperature  required.  This  is  best 
effected  by  passing  it  through  a  coil  surrounded  by  hot  water. 
Fig.  34  shows  an  apparatus  especially  adapted  for  heating  the 
alcoholic  liquid.  In  a  copper  or  iron  boiler  filled  with  water, 
which  can  be  heated  from  below,  is  a  coil,  S,  of  pure  tin ;  it 
enters  the  boiler  above  at  a  and  leaves  it  at  6,  so  that  the  place 
of  inflow  is  at  the  same  level  with  that  of  outflow.  With 
this  form  of  construction  the  coil  of  course  remains  always 
filled  with  liquid,  which  with  the  use  of  pure  tin  is,  however, 
of  no  consequence ;  besides,  this  can  be  remedied  by  placing 
on  the  lower  coil  a  narrow  pipe,  R,  which  projects  above  the 
edge  of  the  boiler  and  is  bent  like  a  siphon.  By  opening  the 
spigot  h  the  fluid  contained  in  the  coil  runs  off  through  R. 

^The  rising  pipe  of  the  forcing-pump  is  provided  with  an 
arrangement  by  which  the  alcoholic  liquid  can  be  brought 
either  directly  from  the  collecting  vessel  into  the  reservoirs,  or 
first  forced  through  the  heating  apparatus.  It  consists  of  a 
prismatic  wooden  body  provided  with  three  spigots.  By  clos- 
ing spigots  2  and  3  and  opening  1,  the  alcoholic  liquid  is 
immediately  conveyed  from  the  collecting  vessels  to  the  reser- 
voirs. By  closing  spigot  1  and  opening  2  and  3,  which  are 
connected  by  short  pieces  of  rubber  hose  with  the  ends  of  the 
coil,  S,  the  alcoholic  liquid  forced  upward  from  the  collecting 
vessels  by  the  pump  must  pass  through  the  heating  coil,  and 
after  being  heated  it  returns  to  the  rising  pipe,  which  conveys 
it  to  the  reservoirs.  The  arrows  in  the  illustration  indicate 
the  course  of  the  alcoholic  liquid  has  to  traverse  when  spigots 
2  and  3  are  open  and  1  closed. 

The  diameter  and  length  of  the  tin  coil  depends  on  the 
quantity  of  fluid  which  is  to  pass  through  it,  though  one  with 
a  clear  diameter  of  12  to  14  inches  and  a  length  of  23  to  26 
feet  will,  as  a  rule,  suffice.  Besides  by  slower  or  quicker 
pumping  the  fluid  can  be  forced  with  less  or  greater  velocity 
through  the  coil  and  correspondingly  more  or  less  heated. 


96  MANUFACTURE    OF    VINEGAR. 

The  walls  of  the  coil  should  be  as  thin  as  possible  so  as  to 
yield  heat  rapidly. 

The  heating  of  the  alcoholic  liquid,  of  course,  can  also  be 
effected  by  heating  one  portion  more  strongly  than  necessary 
and  reducing  it  to  the  required  temperature  by  mixing  with 
cold  fluid.  In  working,  however,  with  a  fluid  containing  living 
vinegar  ferment — and  such,  as  will  be  explained  later  on,  is 
claimed  to  be  already  contained  in  freshly  prepared  alcoholic 
fluid — care  must  be  had  not  to  heat  the  liquid  above  120°  F., 
this  temperature  being  destructive  to  the  ferment. 


CHAPTER  X. 

OPERATIONS    IN    A    VINEGAR  FACTORY. 

Acetification  of  the  Generators. — The  object  of  acetification  is 
to  thoroughly  saturate  the  filling  material — shavings,  char- 
coal, etc.— of  the  generators  with  vinegar  and  to  cause  the 
development  of  the  vinegar  ferment  upon  it.  The  generators 
are  first  filled  with  the  filling  material,  the  false  heads  or 
the  spargers  are  next  placed  in  position,  and  the  temperature 
of  the  workroom  is  brought  up  close  to  86°  F.  For  acetifica- 
tion, i.  e.,  saturating  the  shavings,  vinegar  of  the  same 
strength,  i.  e.,  with  the  same  content  of  acetic  acid  as  that 
which  is  to  be  prepared  in  the  generators,  is  used.  For  every 
35J  cubic  feet  of  the  space  filled  with  shavings  or  charcoal  are 
required  for  complete  acetification  the  following  quantities  of 
vinegar : 

For  shavings  loosely  poured  in 60|  to  71£  gallons. 

For  shavings  piled  up  one  alongside  the  other  ..90  to  105£  gallons. 
For  charcoal,  the  size  of  a  walnut   142J  to  211  \  gallons. 

The  value  of  the  vinegar  used  for  acetification  has  to  be 
considered  as  dead  capital. 


OPERATIONS    IN    A    VINEGAR    FACTORY.  97 

The  first  vinegar  running  off  from  the  generators  is  not  only 
considerably  weaker  than  that  used  for  acetification,  but,  not- 
withstanding the  previous  lixiviation  of  the  wood,  has  a  dis- 
agreeable taste  so  as  to  render  it  unfit  for  the  preparation  of 
table  vinegar,  and  can  only  be  utilized,  for  instance,  in  the 
preparation  of  acetate  of  lead,  etc.  When  the  vinegar  running 
off  exhibits  a  pure  taste,  it  is  collected  by  itself  and  later  on 
converted  into  a  product  of  greater  strength  by  mixing  it  with 
alcohol  and  passing  again  through  the  generators.  By  this 
saturation  of  the  shavings  with  vinegar,  the  vinegar  ferment 
locates  in  abundance  upon  the  surface  of  the  shavings,  and 
the  generators  are  fit  for  the  formation  of  vinegar. 

Regular  production,  however,  can  be  commenced  only  grad- 
ually, which  may  be  illustrated  by  an  example  as  follows : 

At  first,  for  instance,  alcoholic  liquid  is  introduced  only 
once  a  day,  either  early  in  the  morning  or  in  the  evening. 
In  about  eight  days,  or  under  certain  conditions  even  later, 
the  temperature  in  the  generators  has  risen  to  from  86°  to  95° 
F.,  and  alcoholic  liquid  may  now  be  introduced  twice  daily, 
for  instance,  early  in  the  morning  and  in  the  afternoon.  The 
fact  that  the  generator  is  working  is  recognized  by  the  in- 
creased temperature  and  by  the  flame  of  a  candle  held  near  a 
draught-hole  being  drawn  inwards.  After  eight  to  fourteen 
days  more  the  thermometer  shows  96°  to  98°  F.,  and  then 
alcoholic  liquid  is  introduced  three  times  daily,  for  instance, 
early  in  the  morning,  in  the  forenoon  and  in  the  afternoon, 
whereby  the  temperature  rises  to  102°  or  104°  F.  If  now  the 
vinegar  running  off  shows  the  desired  strength,  the  generators 
are  in  good  working  order,  and  are  subjected  to  the  regular 
treatment. 

Accelerated  Acetification. — By  closely  considering  the  process 
which  must  take  place  in  acetification  and  the  first  stage  of 
the  operation,  it  will  be  plainly  seen  that  the  above-described 
method  cannot  be  called  a  rational  one,  there  being  a  waste  of 
time  as  well  as  of  material,  and  the  commencement  of  regular 
working  being  largely  dependent  upon  accident. 
7 


98  MANUFACTURE    OF    VINEGAR. 

The  object  of  Rectification  is,  as  previously  stated,  first  to 
thoroughly  saturate  the  shavings  with  vinegar  and  next  to 
develop  the  vinegar  ferment  upon  them.  This  can,  however, 
be  attained  in  a  more  suitable  and  a  quicker  manner  than  by 
the  above  process. 

Air-dry  wood  contains  on  an  average  20  per  cent,  of  water, 
and  during  acetification  this  water  must  be  gradually  replaced 
by  vinegar ;  hence  the  vinegar  trickling  from  the  generators 
will  remain  poor  in  acetic  acid  and  rich  in  water  until  the 
shavings  are  entirely  saturated  with  pure  vinegar  and  the 
water  has  been  expelled. 

The  removal  of  the  water  from  the  shavings  and  its  substitu- 
tion by  vinegar  are  effected  by  osmose,  i.  e.,  the  cells  of  the 
wood  surrounded  by  vinegar  yield  a  fluid  consisting  of  water 
and  extractive  substances  of  the  wood  and  absorb  sufficient  of 
the  exterior  fluid  until  both  liquids  have  the  same  composition. 
Now,  by  pouring  only  a  small  quantity  of  vinegar  at  one  time 
over  the  shavings  in  the  generator,  as  is  done  in  acetification 
according  to  the  old  method,  the  course  of  the  process  is  very 
slow,  14  days  or  more,  as  already  mentioned,  being  required 
before  the  vinegar  running  off'  shows  no  longer  a  change  in  its 
concentration. 

In  a  generator  in  a  stage  of  acetification  an  uninterrupted, 
though  slight,  current  of  air  upwards  takes  place,  since  even 
with  the  use  of  the  best  heating  apparatus  the  air  in  the  upper 
layers  is  warmer  than  in  the  lower.  This  current  of  air  be- 
comes stronger  with  the  development  of  larger  quantities  of 
vinegar  ferment  and  causes  a  large  absolute  loss  of  vinegar. 
The  greater  portion  of  this  loss  must  be  set  down  as  being  due 
to  evaporation,  which  must  be  considerable  on  account  of  the 
great  surface  over  which  the  vinegar  is  distributed,  and  the 
smaller  portion,  to  consumption  by  the  vinegar  ferment. 

By  placing  the  shavings  in  vinegar  the  above-described  pro- 
cess of  substitution  of  vinegar  for  the  fluid  contained  in  the 
cells  of  the  wood  takes  place  very  quickly,  and,  theoretically, 
it  would  therefore  seem  to  be  advisable  to  follow  the  same 


OPERATIONS    IN    A    VINEGAR    FACTORY.  99 

course  on  a  large  scale,  i.  e.,  to  saturate  the  shavings  with 
vinegar  before  placing  them  in  the  generators.  By  using 
artificially  dried  shavings  (see  p.  54)  the  saturation  is  effected 
in  the  course  of  a  few  hours,  the  dry"  woody  tissue  absorbing 
the  fluid  like  a  sponge. 

The  shavings,  while  still  hot,  are  brought  into  a  vat  and 
covered  with  the  vinegar  to  be  used  for  acetification.  In  about 
12  hours  they  are  thoroughly  saturated.  The  excess  of  vine- 
gar is  drawn  off  through  the  tap-hole  in  the  bottom  of  the  vat, 
and  having  absorbed  neither  water  nor  extractive  substances 
from  the  steamed  and  thoroughly  dried  shavings  can  be  imme- 
diately re-used  for  the  saturation  of  another  portion  of  shav- 
ings. The  saturated  shavings  are  at  once  used  for  filling  a 
generator,  and  the  latter,  which  may  now  be  considered  as 
completely  acetified,  can  at  once  be  employed  for  the  process 
of  the  formation  of  vinegar  according  to  the  method  described 
below. 

Instead  of  in  a  vat,  the  shavings  can  also  be  saturated 
directly  in  the  generator.  For  this  purpose  the  shavings, 
after  having  been  artificially  dried,  are  immediately  brought 
into  the  generator,  and  vinegar  is  poured  over  them  either  by 
means  of  the  false  head  or  the  sparger  until  a  considerable 
quantity  has  accumulated  in  the  space  below  the  false  bottom. 
This  accumulation  is  then  drawn  off  and  again  poured  over 
the  shavings,  this  being  continued  until  they  are  thoroughly 
saturated,  which  is  effected  in  a  comparatively  short  time. 

Induction  of  the  Operation  with  an  Artificial  Culture  of  Vinegar 
Ferment. — In  the  process  of  accelerated  acetification  of  the 
generators  no  development  of  vinegar  ferment  can  of  course 
take  place,  since  by  heating  the  shavings  to  about  212°  F. 
any  fermenting  organisms  accidentally  adhering  to  them  are 
destroyed.  The  vinegar  ferment  increases  with  astonishing 
rapidity  provided  it  finds  nutriment  suitable  for  its  develop- 
ment. Vinegar  is,  however,  a  very  poor  material  for  this 
purpose,  and  this  is  very  likely  the  reason  why  weeks  are  re- 
quired before  production  can  be  commenced  in  generators 


100  MANUFACTURE    OF    VINEGAR. 

acetified  according  to  the  old  method.  The  ferment  cany 
however,  be  so  rapidly  propagated  in  the  generator  that  pro- 
duction can  be  commenced  almost  immediately  after  acetifi- 
cation  is  complete. 

For  this  purpose  a  method  similar  to  that  employed  in  the 
manufacture  of  alcohol  and  yeast  has  to  be  pursued  and  vigor- 
ous ferment  obtained  by  cultivation.  As  previously  mentioned, 
the  ferment  causing  acetic  fermentation  is  widely  distributed 
throughout  nature  and  is  most  abundantly  found  in  the  air  of 
thickly  populated  regions. 

The  "pure  culture"  of  the  vinegar  ferment,  i.  e.,  in  which 
no  other  than  the  desired  ferment  is  developed,  is  not  diffi- 
cult, it  being  only  necessary  to  prepare  a  fluid  especially 
adapted  for  its  nutriment  and  allow  it  to  stand  at  a  suitable 
temperature  in  order  to  obtain  in  a  few  days  a  vigorous 
growth  produced  by  a  few  individual  germs  reaching  the  fluid 
from  the  air.  The  best  fluid  for  the  purpose  is  one  which  con- 
tains, besides  a  large  quantity  of  water — about  85  to  90  per  cent. 
— a  certain  amount  of  alcohol  and  acetic  acid,  and  very  small 
quantities  of  nitrogenous  substances  and  mineral  salts.  Hence 
its  preparation  is  not  difficult,  it  being  only  necessary  to  mix 
ordinary  vinegar  and  alcohol  in  suitable  proportions  and  add  a 
small  quantity  of  a  fluid  containing  nitrogenous  substances 
and  mineral  salts,  such  as  wine,  cider,  beer  or  malt  extract. 
Numerous  experiments  have  shown  that  a  fluid  containing 
from  4  to  6  per  cent,  of  acetic  acid  and  the  same  quantity  of 
'alcohol  with  the  addition  of  a  small  quantity  of  one  of  the 
above-mentioned  fluids  is  best  adapted  for  the  vigorous  nour- 
ishment of  the  vinegar  ferment.  Ordinary  table  vinegar  con- 
tains as  a  rule  from  4  to  6  per  cent,  of  acetic  acid  ;  the  average 
percentage  of  alcohol  is  in  wine  from  8  to  10  ;  in  cider  from 
4  to  6 ;  and  in  beer  from  3  to  5.  Taking  this  statement  as  a 
guide,  the  preparation  of  a  fluid  containing  from  4  to  6  per 
cent,  of  acetic  acid,  4  to  G  per  cent,  of  alcohol,  and  the  required 
nitrogenous  combinations  and  salts  will  not  be  diflicult. 

Fluids  of  this  composition  are  obtained  by  mixing,  for  in- 


OPERATIONS    IN    A    VINEGAR    FACTORY.  101 

stance,  equal  parts  of  cider  and  vinegar,  or  one  part  of  wine 
with  two  of  vinegar,  or  one  part  of  beer  with  three  of  vinegar, 
and  adding  5  per  cent,  of  90  per  cent,  alcohol  to  the  mixture. 
Such  mixtures,  possessing  the  power  of  vigorously  nourishing 
the  vinegar  ferment,  can  at  the  same  time  be  considered  as 
types  for  the  preparation  of  alcoholic  liquid  of  suitable  com- 
position. 

To  assure  the  exclusive  development  of  vinegar  ferment 
upon  any  of  the  above-mentioned  mixtures  it  is  best  to  heat 
it  to  the  boiling-point  of  water.  Young  wine  as  well  as  cider 
contains  considerable  quantities  of  albuminous  substances  in 
solution,  and  fluids  of  this  nature  being  well  adapted  for  the 
nutriment  of  the  mold  ferment,  the  development  of  the  latter 
might  increase  to  such  an  extent  as  entirely  to  suppress  the 
vinegar  ferment  and  thus  render  its  cultivation  a  failure. 
Beer  is  also  very  suitable  for  the  nutriment  of  the  mold  fer- 
ment, though  in  a  less  degree  than  young  wine,  and  besides 
living  yeast,  contains  alcoholic  ferment. 

By  heating  wine  or  beer  only  for  a  moment  to  about  158° 
P.,  a  large  portion  of  the  albuminous  substances  in  solution 
becomes  insoluble,  and  on  cooling  separates  as  a  flaky  precipi- 
tate, all  ferments  present  in  the  fluid  being  at  the  same  time 
destroyed.  Hence  for  the  preparation  of  a  fluid  especially 
adapted  for  the  cultivation  of  pure  vinegar  ferment,  it  is 
recommended  quickly  to  heat  to  the  boiling  point  1  quart  of 
ordinary  white  wine  in  a  covered  porcelain  vessel,  and  after 
cooling  to  the  ordinary  temperature,  to  mix  it  with  2  quarts 
of  vinegar.  To  remove  the  separated  insoluble  albuminous 
substances,  filter  through  blotting  paper. 

To  prepare  a  nourishing  fluid  from  beer,  heat  a  quart  of  it 
to  the  boiling  point,  mix  it  after  cooling  with  3  quarts  of 
vinegar,  add  J  quart  of  90  per  cent,  alcohol,  and  filter. 

Distribute  this  fluid  in  a  number  of  shallow  porcelain  vessels 
and  place  the  latter  near  a  window  in  the  heated  workroom. 
To  prevent  dust  from  falling  into  the  fluid,  cover  each  dish  with 
a  glass  plate  resting  upon  two  small  wooden  sticks  placed 


102  MANUFACTURE    OF    VJNKGAR. 

across  the  dish.  In  two  or  three  days,  and  sometimes  in  24 
hours,  the  commencement  of  the  development  of  the  vinegar 
ferment  will  be  recognized  by  the  stronger  odor  of  vinegar  than 
that  possessed  by  the  original  fluid  and  by  the  appearance  of 
the  surface  of  the  liquid.  By  observing  the  latter  at  a  very 
acute  angle,  dull  patches  resembling  grease-stains  and  consist- 
ing of  a  large  number  of  individuals  of  the  vinegar  ferment 
will  be  seen.  In  a  few  hours  these  patches  will  have  increased 
considerably,  until  finally  the  entire  surface  appears  covered 
by  a  very  delicate  veil-like  layer  of  vinegar  ferment. 

By  touching  the  surface  with  the  point  of  a  glass  rod  a  cer- 
tain amount  of  the  coating  adheres  to  it,  and  by  rinsing  it  off 
in  a  fluid  of  similar  composition  not  yet  impregnated,  the  fer- 
ment quickly  develops  upon  it.  By  placing  a  drop  of  the  fluid 
under  the  microscope  a  picture  similar  to  that  shown  in  Fig. 
2,  p.  14,  presents  itself,  the  entire  field  of  vision  being  covered 
with  germs  of  vinegar  ferment. 

By  the  development  of  mold  ferment  the  cultivation  of  pure 
vinegar  ferment  may  sometimes  result  in  failure  even  with  the 
use  of  the  above-mentioned  fluids.  The  development  of  this 
ferment  is  recognized  by  the  appearance  of  white  dots  upon 
the  fluid,  which  quickly  increase  to  white  opaque  flakes,  and  if 
left  to  themselves  finally  combine  to  a  white  skin  of  a  peculiar 
wrinkled  appearance.  Fig.  35  shows  a  microscopical  picture 
of  such  abortive  culture  of  vinegar  ferment.  By  observing 
at  the  commencement  of  this  phenomenon  the  fluid  with  the 
microscope,  very  small  individuals  of  vinegar  ferment,  6,  will 
be  observed  alongside  of  the  much  larger  oval  cells  a,  of  the 
mold  ferment.  Such  fluid  being  not  adapted  for  our  purposes 
has  to  be  thrown  away  and  the  dish  rinsed  off  with  boiling 
water. 

When  the  fluid  in  the  dishes  is  entirely  covered  with  pure 
vinegar  ferment,  it  is  poured  into  a  vessel  containing  the 
greater  portion  of  the  alcoholic  fluid  intended  for  the  first 
charge  of  the  generators,  and  in  the  course  of  10  hours  the 
entire  surface  of  this  fluid  is  covered  with  vinegar  ferment. 


OPERATIONS    IN    A    VINEGAR    FACTORY. 


103 


This  fluid  being  poured  into  the  sufficiently  acetified  genera- 
tors and  trickling  gradually  through  them,  the  greater  portion 
of  the  ferment  adheres  to  the  shavings,  and  increases  with 
such  rapidity  that  the  great  rise  of  temperature  in  the  interior 
of  the  generators  shortly  indicates  the  regular  beginning  of 
their  activity,  and  the  pouring  in  of  alcoholic  liquid  can  at 
once  be  commenced. 

Vinegar  ferment  developed  upon  one  of  the  above-mentioned 
fluids  is  evidently  so  constituted  that  it  can  be  thoroughly 


'^t  i'  l  A. 

n  tvf      <#>       y         _/: 

/    Q  V  « 

/      ^       /         •  ^v        . 

/      :/      '       ,-.  ,.       ,.'•'•?' 


,   &*&** 


nourished  by  it,  and  hence  the  generators  might  be  continued 
to  be  charged  with  alcoholic  liquid  of  a  corresponding  com- 
position. It  being,  however,  as  a  rule,  desired  to  manufacture 
as  strong  a  product  as  possible,  an  alcoholic  liquid  much  richer 
in  alcohol  than  the  above-mentioned  nourishing  fluids  has  to 
be  used. 

By,  however,  suddenly  changing  the  nourishing  fluid  of  the 
vinegar  ferment,  for  instance,  from  a  fluid  containing  only  4 
to  6  per  cent,  of  alcohol  to  one  with  12  to  13  per  cent.,  the 
action  of  the  ferment  would  very  likely  be  sluggish  before  it 


104  MANUFACTURE    OF    VINEGAR. 

became  accustomed  to  the  new  conditions.  Further,  its 
activity  might  suffer  serious  disturbance  and  its  propagation 
decrease  very  sensibly,  so  that  notwithstanding  strong  heating 
of  the  workroom  and  thorough  ventilation  of  the  generators, 
the  temperature  in  the  latter  would  suddenly  fall,  and  would 
only  be  restored  to  the  required  degree  after  the  ferment  had 
become  accustomed  to  the  new  conditions  and  recommenced 
its  vigorous  propagation. 

To  overcome  such  annoying  disturbances, 'it  is  only  neces- 
sary to  gradually  change  the  composition  of  the  nourishing 
fluid  to  that  which  the  alcoholic  liquid  to  be  worked  in  the 
generators  is  to  have.  Commencing,  for  instance,  with  an  alco- 
holic liquid  containing  5  per  cent,  of  alcohol,  the  next  day 
one  with  6  per  cent,  is  used,  the  succeeding  day  one  with  7 
per  cent.,  and  so  on  until  the  maximum  percentage  of  alcohol 
the  liquid  is  to  have  is  reached. 


CHAPTER  XI. 

PREPARATION    OF    THE    ALCOHOLIC    LIQUID. 

BY  the  term  "  alcoholic  liquid"  is  to  be  understood  every 
kind  of  fluid  to  be  converted  into  vinegar  which,  besides  water 
and  small  quantities  of  nourishing  salts  and  albuminous  sub- 
stance, does  not  contain  over  14  per  cent,  of  alcohol.  The 
term  "  wash  "  or  "  mixture  "  is  frequently  applied  to  the  alco- 
holic liquid.  In  the  directions  generally  given  for  the  prepa- 
ration of  such  liquids,  vinegar  is  mentioned  as  an  indispensa- 
ble constituent.  While  it  cannot  be  denied  that  a  content  of 
vinegar  in  the  alcoholic  liquid  exerts  a  favorable  effect-upon 
the  formation  of  vinegar,  it  must  be  explicitly  stated  that  it  is 
not  the  acetic  acid  in  the  vinegar  which  in  this  case  becomes 
active,  but  the  ferment  contained  in  it. 

In  a  vinegar  factory,  vinegar  just  finished  and  quite  turbid 
is  as  a  rule  used  in  the  preparation  of  alcoholic  liquid,  and  a 


PREPARATION    OF    THE    ALCOHOLIC    LIQUID.  105 

microscopical  examination  shows  such  vinegar  to  contain  in- 
numerable germs  of  vinegar  ferment.  This  ferment  on  com- 
ing in  contact  with  much  air  in  the  generators  will  evidently 
increase  rapidly  and  contribute  to  the  rapid  acetification  of  the 
alcohol.  That  it  is  actually  the  ferment  in  the  vinegar  used 
which  exerts  a  favorable  effect  can  be  shown  by  a  simple  ex- 
periment. By  adding  vinegar  previously  heated  to  from  140° 
to  158°  F.  to  the  alcoholic  liquid,  the  formation  of  vinegar  in 
the  generators  proceeds  more  slowly,  the  ferment  contained  in 
the  vinegar  having  been  killed. 

The  best  proof,  however,  that  the  alcoholic  liquid  does  not 
require  any  considerable  quantity  of  acetic  acid  for  its  conver- 
sion into  vinegar  is  furnished  by  the  behavior  of  wine.  Prop- 
erly prepared  wine  of  a  normal  composition  contains  only  a 
few  ten-thousandths  of  its  weight  of  acetic  acid,  and  this  must 
very  likely  be  considered  as  ar  product  of  vinous  fermentation. 
If  such  wine  be  stored  for  years  in  a  cool  cellar,  its  content  of 
acetic  acid  does  not  change.  By,  however,  exposing  it  in  a 
shallow  vessel  to  the  air  at  from  66°  to  78°  F.,  microscopical 
examination  will  show  the  development  of  vinegar  ferment  upon 
it,  and  a  chemical  analysis  a  constant  increase,  soon  amounting 
to  several  per  cent,  of  acetic  acid.  A  fluid  composed  of  5  to  & 
per  cent,  of  alcohol,  94  to  95  per  cent,  of  water,  and  a  very 
small  quantity  of  malt  extract,  acts  in  a  similar  manner.  In 
many  cases  the  vinegar  ferment  is  developed  without  the  fluid 
containing  acetic  acid. 

The  alcoholic  fluid  to  be  used  may  from  the  start  contain  a 
sufficiently  large  percentage  of  alcohol  to  correspond  to  the  de- 
sired strength  of  the  vinegar  to  be  made,  and  in  this  case  the 
fluid  has  to  be  poured  several  times  into  the  generators,  it 
being  impossible  to  convert  a  large  quantity  of  alcohol  into 
acetic  acid  by  passing  it  through  but  once.  By  another 
method  an  alcoholic  liquid  is  first  prepared  containing  but 
little  alcohol,  which  is  almost  completely  converted  into  acetic 
acid  by  one  passage  through  the  generators.  The  fluid  run- 
ning off  from  the  generators  is  then  further  mixed  with  a  cer- 


106  MANUFACTURE    OF    VINEGAR. 

tain  quantity  of  alcohol,  and  being  poured  into  a  generator  in 
which  the  vinegar  ferment  is  already  accustomed  to  larger 
quantities  of  alcohol  and  vinegar,  is  also  converted  into  acetic 
acid.  More  alcohol  can  then  be  added,  and  so  on.  The  last 
method  is  evidently  the  best  as  regards  the  conditions  of  life 
of  the  vinegar  ferment,  and  actually  the  only  one  by  which 
the  strongest  vinegar  (with  from  12  to  13  per  cent,  of  acetic 
acid)  can  be  obtained  in  generators. 

That  it  is  advisable  only  gradually  to  increase  the  content 
of  alcohol  in  the  alcoholic  liquid  is  shown  by  the  behavior  of 
the  ferment  towards  alcohol  and  acetic  acid.  Both  bodies,  if 
present  in  large  quantities,  are  decidedly  inimical  to  the  prop- 
agation of  the  ferment,  a  fluid  containing  from  14  to  15  per 
cent,  of  alcohol,  or  as  much  acetic  acid,  being  capable  of  check- 
ing it  to  such  an  extent  as  to  disturb  the  process  of  production. 

Another  argument  against  the  use  of  the  total  quantity  of  al- 
cohol in  the  preparation  of  the  alcoholic  liquid  to  be  employed 
for  the  first  pouring,  is  the  fact  that  evidently  more  alcohol  will 
be  lost  by  evaporation  than  by  commencing  with  a  fluid  con- 
taining less  alcohol,  and  adding  a  corresponding  quantity  of 
the  latter  after  the  fluid  has  once  passed  through  the  genera- 
tors. The  quantity  .of  alcohol  for  the  first  pouring  should  be  so 
chosen  that  the  fluid  running  off  still  contains  a  small  quantity 
of  unchanged  alcohol,  this  being  an  assurance  that  only  alcohol 
and  not  unfinished  acetic  acid  has  undergone  an  alteration. 
So  long  as  alcohol  is  present  in  the  alcoholic  liquid  the  vinegar 
ferment  is  almost  entirely  indifferent  towards  acetic  acid,  but 
after  the  oxidation  of  all  the  alcohol,  it  attacks  the  acetic  acid 
and  decomposes  it  to  carbonic  acid  and  water.  This  can  be 
shown  by  a  very  simple  experiment.  If  finished  vinegar,  in- 
stead of  alcoholic  liquid,  be  poured  into  a  generator  in  full 
operation,  the  vinegar  running  off  shows  a  smaller  percentage 
of  acetic  acid  than  that  poured  in,  the  acetic  acid  missing 
having  been  destroyed  by  the  ferment. 

To  what  an  extent  even  smaller  quantities  than  14  to  15 
per  cent,  of  alcohol  or  acetic  acid  exert  a  restraining  influence 


PREPARATION    OF    THE    ALCOHOLIC    LIQUID.  107 

upon  the  propagation  and  activity  of  the  vinegar  ferment  can 
be  seen  in  generators  charged  with  alcoholic  liquid  of  different 
strengths,  those  containing  less  concentrated  liquid  can  in  the 
same  time  form  a  much  larger  quantity  of  acetic  acid  than 
those  in  which  a  liquid  is  used  which  already  contains  certain 
quantities  of  acetic  acid.  Hence,  the  greater  the  quantity  of 
acetic  acid  already  contained  in  the  alcoholic  liquid,  the  slower 
the  conversion  of  the  alcohol  still  present  in  the  acetic  acid. 

It  may,  therefore,  be  laid  down  as  a  rule  that  the  manufac- 
turer should  not  strive  to  prepare  vinegar  with  more  than  about 
12  per  cent,  of  acetic  acid.  Though  in  exceptional  cases  a 
product  with  13  per  cent,  can  be  obtained,  it  will  also  be  ob- 
served that  the  respective  generators  gradually  yield  a  weaker 
product,  or  that  their  activity  suddenly  ceases  to  such  an 
extent  as  to  require  them  to  be  placed  out  of  operation. 

The  preparation  of  high-graded  vinegar  being  undoubtedly 
subject  to  greater  difficulties  than  that  of  a  weaker  product, 
the  question  might  be  raised  whether  the  manufacture  of  weak 
vinegar  only  would  not  be  the  most  suitable.  This  must  be 
largely  decided  by  local  conditions.  For  a  manufacturer  whose 
custom  lies  in  the  immediate  neighborhood,  for  instance,  in  a 
large  city,  the  production  of  weak  vinegar  only  would  be  advis- 
able; but  if  he  has  to  send  his  product  a  considerable  distance, 
the  fact  that  the  more  freight  has  to  be  paid  on  what  is  of  no 
value,  the  weaker  the  vinegar  is,  and  that  the  expense  of  trans- 
porting a  strong  article  is  relatively  less,  deserves  considera- 
tion. The  consumer  can  readily  prepare  vinegar  of  any 
described  strength  by  diluting  the  strong  product  with  water. 

The  quantity  of  beer  required  for  the  purpose  of  offering 
suitable  nutriment  to  the  vinegar  ferment  is  very  small,  an  ad- 
dition of  1  per  cent,  to  the  alcoholic  liquid  being  ample.  Sour 
or  stale  beer  can  of  course  be  used.  The  reason  for  the  em- 
ployment of  larger  quantities  of  beer  in  mixing  the  alcoholic 
fluids  is  found  in  the  fact  that  the  vinegar  prepared  from  such 
mixtures  sooner  acquires  a  pure  taste  than  that  made  from 
fluids  containing  but  little  beer.  The  addition  of  beer  should, 


108 


MANUFACTUKE    OF    VINECJAK. 


however,  not  exceed  15  per  cent,  of  the  total  quantity  of  alco- 
holic liquid,  as  on  account  of  the  comparatively  high  percent- 
age of  albuminous  substances  and  the  maltose,  dextrin,  and 
extractive  matters  of  hops  it  contains,  a  larger  quantity  would 
be  injurious  to  the  process  of  acetic  fermentation,  the  genera- 
tors being  frequently  rendered  inactive  by  the  so-called  "  slim- 
ing of  the  shavings."  The  production  of  the  latter  is  due  to 
the  fact  that  by  being  partially  excluded  from  contact  with  the 
air  by  the  comparatively  thick  fluid  passing  over  it,  the  vine- 
gar ferment  deposited  upon  the  shavings  assumes  the  form  of 
mother  of  vinegar  which  adheres  to  the  shavings  as  a  slimy 
mass. 

The  quantity  of  finished  vinegar  added  to  the  alcoholic 
liquid  varies  between  10  and  33  per  cent.  The  use  of  large 
quantities  is  however  decidedly  inexpedient,  since  the  only 
effect  produced  by  the  vinegar  is,  as  previously  stated,  due  to 
the  ferment  contained  in  it.  Of  freshly  prepared,  turbid  vine- 
gar, 10  per  cent,  is  ample  for  the  preparation  of  alcoholic 
liquid,  and  a  greater  quantity  can  only  be  considered  as  use- 
less ballast. 

Theoretically  a  certain  quantity  of  alcohol  yields  exactly  a 
certain  quantity  of  acetic  acid.  The  following  table  shows  the 
proportions  between  the  two  bodies  : — 


I 

—  .' 

A    mixture  con- 
taining the  follow- 

Is composed  by 
weight  of 

And  yields 

Total 

o>  "f: 
fj. 

ing     per    cent,     of 

vinegar. 

alcohol  by  volume 

Alcohol. 

Water. 

Acetic 
anhydride. 

Water. 

I" 

1 

0.8 

99.2 

10 

99.5 

100.5 

1.0 

2 

1.6 

98.4 

2.1 

99.0 

101.1 

2.1 

3 

2.4 

97.6 

3.1             98.5 

101.6 

3.1 

4 

3.2 

96.8 

4.2            98.0           102.2 

4.1 

5 

4.0 

96.0 

5.2            97.6 

102.8 

5.1 

6 

4.8 

95.2 

6.3            97.1 

103.3 

6.0 

7 

5.6 

94.4 

7.3  .         96  6 

103.9 

7.0 

8 

6.4 

93.6 

8.3 

96.1 

104.4 

80 

9 

7.2 

92.8 

9.4 

95.6 

105.0 

'  8.9 

10 

8.1 

91.9 

10.4 

950 

105.4 

9.9 

11 

8.9 

91.1 

11.6 

94.6 

106  2 

10.9 

12                      9.7 

90.3 

12.6 

94.1 

106.7 

11.8 

PREPARATION    OF    THE    ALCOHOLIC    LIQUID. 


109 


Practically  less  vinegar  with  a  smaller  percentage  of  acetic 
anhydride  is,  however,  always  obtained,  this  being  due  to  losses 
of  material  caused  partially  by  evaporation  and  partially  by 
the  oxidation  of  the  alcohol  extending  beyond  the  formation 
of  acetic  acid.  In  preparing  the  alcoholic  liquid  these  un- 
avoidable losses  must  be  taken  into  consideration,  and  more 
alcohol  has  to  be  used  for  the  production  of  vinegar  with  a  de- 
termined percentage  of  acetic  acid  than  is  theoretically  re- 
quired. How  much  more  has  to  be  taken  depends  on  the 
kind  of  apparatus  used  and  on  the  strength  the  vinegar  to  be 
prepared  is  to  show.  The  higher  the  percentage  of  acetic  acid 
which  is  to  be  obtained,  the  greater  the  losses  will  be,  and  con- 
sequently the  greater  the  content  of  alcohol  in  the  alcoholic 
liquid  must  be.  Theoretically  one  per  cent,  of  alcohol  yields 
one  per  cent,  of  acetic  acid,  but  practically  the  proportions  are 
as  follows : 


For  the  production  of 
vinegar  with  a  con- 
tent of  acetic  acid  of— 

5  per  cent    . 
6 

7 
8 


10 
11 
12 


Is  required  an  alcoholic 
liquid  with  a  content 
of  alcohol  of— 

5.4  to  5.5  per  cent. 
6.5"    0.6 

7.6  k'    7.7 

8.7  k'    88 
9.8 -k    99 

10.9  ^  11.0 
11.9  "  12.1 
13.0  "  13.2 


The  strength  of  commercial  alcohol  varying  considerably,. it 
is  of  importance  to  the  manufacturer  to  be  able  to  calculate  in 
a  simple  manner  how  many  gallons  of  water  have  to  be  added 
to  alcohol  of  known  strength  in  order  to  obtain  an  alcoholic 
liquid  with  the  desired  percentage  of  alcohol.  The  calcula- 
tion is  executed  as  follows  : — 

Suppose : 

p  =  per  cent,  of  alcohol  in  the  spirits  to  be  used. 

E  =  per  cent,  of  alcohol  in  the  alcoholic  liquid  to  be  pre- 
pared, the  quotient  obtained  by  dividing  P  by  E  gives  the 
volume  to  which  the  spirits  have  to  be  reduced  by  the  addi- 


110  MANUFACTURE    OF    VINEGAR. 

tion  of  water  in  order  to  obtain  alcoholic  liquid  with  the  de- 
sired percentage  of  alcohol. 

Example : — 

From  spirits  of  86  per  cent.  Tralles',  alcoholic  liquid  with 

11  per  cent,  of  alcohol  is  to  be  prepared. 

P  =  86  ;  E  =  11  ?  =  7.818. 

xL 

Hence  one  volume  of  the  spirits  to  be  used  has  to  be  brought 
to  7.818  volumes,  or  to  one  gallon  of  spirits  6.818  gallons  of 
water  have  to  be  added. 

Examples  of  the  composition  of  alcoholic  liquid  : — 

A.  Alcoholic  liquid  from  alcohol,  water,  and  vinegar : 

For  vinegar  with  about  7  per  cent,  of  acetic  acid. — Alcohol  of 
90  per  cent.  Tr.  10  parts  by  volume,  water  107,  vinegar  with 

7  per  cent,  of  acetic  acid  12. 

For  vinegar  with  about  12  per  cent,  of  acetic  acid. — Alcohol  of 
90  per  cent.  Tr.  10  parts  by  volume,  water  65,  vinegar  with 

12  per  cent,  of  acetic  acid  7. 

It  is  advisable  to  add  about  1  per  cent,  of  the  entire  volume 
of  beer  to  the  above  alcoholic  liquids. 

B.  Alcoholic  liquid  from  alcohol,  water,  vinegar,  arid  beer. 
For  vinegar  with  about  5  per  cent,  of  acetic  acid. — Alcohol  of 

90  per  cent.  Tr.  10  parts  by  volume,  water  107,  vinegar  with 
5  per  cent,  of  acetic  acid  13,  beer  14. 

C.  For  vinegar  with  about  8  per  cent,  of  acetic  acid — Alcohol 
of  90  per  cent.  Tr.  10  parts  by  volume,  water  92,  vinegar  with 

8  per  cent,  of  acetic  acid  10,  beer  9. 

In  many  factories  it  is  customary  not  to  determine  the  com- 
position of  the  alcoholic  liquid  by  calculation,  but  simply  to 
work  according  to  certain  receipts.  Vinegar  of  a  certain  per- 
centage is  obtained,  but  its  strength  cannot  be  predetermined 
with  the  same  nicety  as  by  calculating  the  percentage  of  alco- 
hol in  the  alcoholic  liquid  by  the  above  formula.  The  follow- 
ing may  serve  as  examples  of  such  receipts  : — 


PREPARATION    OF    THE    ALCOHOLIC    LIQUID.  Ill 

D.  Alcohol  of  50  per  cent.  Tr.  100  quarts,  water  600, 
vinegar  900. 

.E.  Alcohol  of  90  per  cent.  Tr.  100  quarts,  water  1200, 
vinegar  300. 

F.  Alcohol  of  90    per  cent.   Tr.   100  quarts,  water  1350, 
vinegar  175,  beer  175. 

G.  Alcohol  of   90    per  cent.   Tr.   100  quarts,  water  1400, 
vinegar  300,  beer  100. 

H.  Alcohol  of  80  per  cent.  Tr.  100  quarts,  water,  850, 
beer  750. 

I.  Alcohol  of  50  per  cent.  Tr.  100  quarts,  water  100,  beer 
100. 

The  mixtures  A,  B  and  C  are  only  given  as  examples  of  how 
alcoholic  liquids  which  yield  vinegar  containing  the  desired 
percentage  of  acetic  acid  are  prepared  according  to  receipts. 
Though  it  may  be  very  convenient  for  the  manufacturer  to 
work  according  to  such  receipts  as  are  given  under  D  to  I, 
their  use  without  a  previous  examination  cannot  be  recom- 
mended. It  is  far  better  for  the  manufacturer  to  prepare  the 
alcoholic  liquid  according  to  a  receipt  of  his  own,  and  not 
shrink  from  the  slight  labor  it  involves.  He  has  then  at  least 
the  assurance  of  obtaining  vinegar  with  exactly  the  percent- 
age of  acetic  acid  desired,  and  is  in  the  position  to  obtain  an 
accurate  view  of  the  entire  process  of  the  operation. 

In  the  United  States  low  wine  containing  12  to  15  per  cent, 
by  volume  of  alcohol  is  as  a  rule  used  for  the  preparation  of 
the  alcoholic  liquid.  Some  manufacturers  prepare  the  sac- 
chariferous  mash  themselves,  allow  it  to  ferment  by  the  addi- 
tion of  yeast,  and  then  distil  off  to  between  12  and  15  per  cent, 
by  volume.  As  the  manufacture  of  yeast  is  frequently  com- 
bined with  that  of  vinegar,  the  distillates  obtained  from  the 
fermented  liquors  are  after  skimming  off  the  yeast  utilized  for 
vinegar  manufacturing  purposes. 

Alcohol  being  the  initial  material  in  the  preparation  of 
alcoholic  liquid,  it  is  necessary  to  know  exactly  the  per  cent, 
by  weight  of  alcohol  it  contains.  With  the  assistance  of  the 


112  MANUFACTURE    OF    VINEGAR. 

tables  at  the  end  of  this  volume,  the  content  of  alcohol  in 
spirits  of  wine  can  be  readily  determined  by  means  of  the 
alcoholometer  and  thermometer. 

With  the  temperature  of  the  spirits  of  wine  at  exactly  59°  F., 
it  suffices  to  determine  its  specific  gravity  by  testing  with  an 
aerometer  and  to  find  the  indicated  figure  in  Table  I  (Hehner's 
alcohol  table).  The  figure  in  the  next  horizontal  column  gives 
the  per  cent,  by  weight,  and  the  next  the  per  cent,  by  volume 
of  alcohol  contained  in  the  spirits  of  wine  examined.  Tables 
II,  III  and  IV  give  data  relating  to  the  proportion  between 
the  specific  gravity  and  per  cent,  by  weight  and  volume  of 
spirits  of  wine  of  various  concentration,  as  well  as  the  decrease 
in  volume  by  mixing  with  water.  Table  V  shows  the  relation 
between  the  statements  of  Tralles'  alcoholometer  and  a  few 
others  used  in  different  places. 

The  specific  gravity  as  well  as  the  volume  of  spirits  of  wine 
varies  with  the  temperature,  and  the  statements  of  the  aero- 
meter for  temperatures  above  the  normal  of  59°  F.  requires  a 
corresponding  correction,  the  execution  of  which  is  simplified 
by  the  use  of  Tables  VI  and  VII.  It  being  desirable,  especially 
during  the  cold  season  of  the  year,  to  raise  the  temperature  of 
the  spirits  of  wine  by  mixing  with  water,  Table  VIII  shows 
how  much  water  has  to  be  added  in  order  to  obtain  from 
105.6  quarts  of  spirits  of  wine  of  known  strength,  whiskey  of 
any  desired  concentration. 

In  order  to  know  exactly  the  yield  of  acetic  acid  which  is 
obtained  from  a  given  quantity  of  alcohol,  the  acetic  acid  con- 
tained in  the  vinegar  added  must  necessarily  be  taken  into 
account  as  well  as  the  alcohol  in  the  beer,  which  is,  of  course, 
converted  into  acetic  acid.  It  is  best  to  make  the  content  of 
alcohol  in  the  alcoholic  liquid  so  that  it  produces  vinegar 
whose  strength  corresponds  with  that  of  the  vinegar  added. 
If,  for  instance,  vinegar  with  7  per  cent,  of  acetic  acid  is  used, 
alcohol  of  7.G  to  7.7  per  cent,  by  weight  would  have  to  be 
employed  according  to  the  table  on  page  109.  The  following 
compilation  shows  the  manner  of  preparing  alcoholic  liquid 
.according  to  rational  principles. 


PREPARATION    OF    THE    ALCOHOLIC    LIQUID.  113 

Suppose  vinegar  with  7  per  cent,  acetic  acid  is  to  be  pre- 
pared. There  would  be  required — 

Spirits  of  wine  of  7.6  to  7.7  per  cent,  by  weight 105.6    quarts. 

Vinegar  with  7  per  cent,  of  acetic  acid  10.56      " 

Beer  .  10.56      " 

Suppose  the  beer  contains,  for  instance,  exactly  3  per  cent, 
by  weight  of  alcohol,  hence  10.58  ounces  in  10.56  quarts. 
According  to  this,  a  result  of  126.78  quarts  of  vinegar  with 
exactly  7  per  cent,  of  acetic  acid  could  not  be  expected,  since 
10.56  quarts  of  the  alcoholic  liquid  do  not  contain,  as  should 
be  the  case,  26.82  to  27.18  ounces  of  alcohol,  but  only  10.58 
ounces.  Hence  actually  to  obtain  vinegar  with  7  per  cent,  of 
acetic  aci$  a  sufficient  quantity  of  spirits  of  wine  will  have 
to  be  added  to  the  alcoholic  liquid  to  increase  the  content  of 
alcohol  by  16.22  to  16.57  ounces,  or  spirit  of  wine  with  more 
than  7.6  to  7.7  per  cent,  by  weight  will  have  to  be  used  from 
the  start. 

It  will,  of  course,  be  understood,  that  the  data  given  above 
hold  good  only  for  the  quality  of  the  vinegar  in  reference  to 
its  content  of  acetic  acid,  the  factor  of  the  qualitative  yield 
being  left  out  of  consideration.  The  material  lost  in  the 
course  of  production  amounts,  as  previously  stated,  to  at  least 
15  per  cent.,  and  in  determining  the  quality  of  the  vinegar 
to  be  produced  this  circumstance  has  to  be  taken  into  con- 
sideration. 

The  content  of  acetic  acid  in  vinegar  can  be  determined  with 
great  ease  and  accuracy  (up  to  T5^  per  cent.)  by  volumetric 
analysis,  and  from  the  result  of  such  determination  it  can  be 
readily  seen  how  near  the  correct  proportion  of  alcohol  in  the 
alcoholic  liquid  has  been  attained,  and  should  the  latter  con- 
tain too  little  of  it,  it  can  be  readily  brought  up  to  the  deter- 
mined percentage  by  the  addition  of  some  strong  spirit  of  wine, 
or,  if  too  much,  by  the  addition  of  some  water. 

Constitution  of  the  Fundamental  Materials  used  in  the  Prepara- 
tion of  Alcoholic  Liquids. — Spirits  of  wine,  water,  vinegar,  and 
8 


114  MANUFACTURE    OF    VINEGAR. 

in  most  cases  beer,  constitute  the  fundamental  materials  for 
the  preparation  oi  alcoholic  liquids. 

.  Any  kind  of  wholesome  drinking  water  is  suitable  for  the 
manufacture  of  vinegar.  Water  containing  a  large  amount  of 
organic  substance  or  living  organisms,  or  which  possesses  a 
specific  taste  from  the  admixture  of  salts,  should  not  be  used 
under  any  circumstance. 

Many  well-waters  are  very  hard,  i.  e.,  they  contain  a  com- 
paratively large  quantity  of  calcium  carbonate  in  solution.  If 
such  water  be  used  in  the  preparation  of  alcoholic  liquid,  the 
calcium  carbonate  is  decomposed  by  the  acetic  acid  and  the 
vinegar  contains  a  corresponding  quantity  of  calcium  acetate 
in  solution.  Other  well-waters  contain  a  large  quantity  of 
gypsum  (calcium  sulphate)  in  solution.  This  salt  is  not 
changed  by  acetic  acid,  but  remains  partially  dissolved  in  the 
finished  vinegar. 

When  water  very  rich  in  gypsum  is  mixed  with  alcohol  the 
fluid,  at  first  entirely  clear,  becomes  in  a  short  time  opalescent 
and  finally  perceptibly  turbid.  After  long  standing  a  very 
delicate  white  sediment  separates  on  the  bottom  of  the  vessel, 
the  fluid  becoming  again  clear.  This  phenomenon  is  ex- 
plained by  the  fact  that  gypsum,  while  soluble  in  water  with 
comparative  ease,  is  next  to  insoluble  in  a  fluid  containing 
alcohol,  and  hence  gradually  separates  in  the  form  of  minute 
crystals. 

Water  containing  no  gypsum  but  much  calcium  carbonate 
shows  after  mixing  with  spirits  of  wine  a  similar  behavior  ;  it 
at  first  becoming  turbid  and  again  clear  after  separating  a  deli- 
cate white  precipitate.  Calcium  carbonate  is  soluble  only  in 
water  containing  a  corresponding  quantity  of  carbonic  acid  ; 
on  standing  in  the  air  the  carbonic  acid  escapes  and  the  cal- 
cium carbonate  separates. 

This  behavior  of  water  when  mixed  with  alcohol  and  stand- 
ing in  the  air  can  be  utilized  for  the  almost  complete  separation 
of  the  gypsum  and  calcium  carbonate.  Mixtures  of  water  and 
alcohol,  in  the  proportion  the  alcoholic  liquids  are  to  have,  are 


PREPARATION    OF    THE    ALCOHOLIC    LIQUID.  115 

first  prepared  and  the  fluid  stored  in  barrels  in  a  warm  apart- 
ment near  the  workroom.  The  mixtures  at  first  turbid  be- 
come clear  after  some  time,  and  are  then  drawn  off  from  the 
sediment  by  means  of  a  rubber  hose.  A  comparative  exami- 
nation of  the  water  and  the  mixtures  shows  that  the  latter 
contain  only  very  small  quantities  of  gypsum  and  calcium 
carbonate  in  solution. 

River  water,  though  generally  soft,  i.  e.,  poor  in  the  above- 
mentioned  salts,  is  seldom  sufficiently  clear  to  be  used  without 
previous  filtration.  It  is  further  very  likely  that  the  small 
worms,  known  as  vinegar  eels,  which  frequently  become  very 
annoying  in  vinegar  factories,  reach  the  alcoholic  liquid 
through  the  use  of  river  water,  and,  therefore,  the  use  of  well- 
water  wherever  possible  is  recommended. 

The  constitution  of  the  spirits  of  wine  used  in  the  prepara- 
tion of  the  alcoholic  liquids  is  of  great  importance,  the  bouquet 
of  the  vinegar  to  be  prepared  depending  on  it.  Commercial 
spirits  of  wine  always  contains  certain  foreign  bodies  known  as 
"  fusel  oils,"  which  have  a  very  intense  odor  and  can  only  be 
removed  by  careful  rectification.  For  the  vinegar  manufac- 
turer it  is  of  great  importance  to  know  the  behavior  of  spirits 
of  wine  containing  fusel  oil  when  converted  into  acetic  acid, 
and  a  number  of  experiments  with  different  varieties  (from 
potatoes,  grain,  wine)  have  shown  the  respective  vinegar  also 
possessed  of  a  specific  odor,  differing,  however,  from  that  of 
the  original  fusel  oil  and  developing  by  storing  into  a  bouquet 
of  a  peculiar  but  agreeable  odor.  This  phenomenon  is  ex- 
plained by  the  fact  that  the  energetic  oxidizing  process  which 
takes  place  in  the  generators  extends  not  only  to  the  alcohol 
but  also  to  the  other  bodies  present,  and  the  greater  portion  of 
the  fusel  oils  is  thereby  converted  into  odoriferous  combina- 
tions or  compound  ethers. 

By  treating  potato  fusel  oil  (amyl  alcohol)  with  sulphuric 
acid  and  an  acetate,  amyl  acetate  is  formed  which  in  a  diluted 
state  smells  like  jargonelle  pears  and  is  used  by  confectioners 
under  the  name  of  "  pear  essence  "  for  flavoring  so-called  fruit 


116  MANUFACTURE    OF    VINEGAR. 

bonbons.  The  same  process  would  seem  to  take  place  by 
passing  spirits  of  wine  containing  potato  fusel  oil  through  the 
generators,  the  vinegar  prepared  from  such  spirits  of  wine 
showing  an  agreeable  odor  immediately  when  running  off 
from  the  generators,  while  vinegar  prepared  from  entirely  pure 
spirits  of  wine  has  at  first  a  stupefying  smell  and  acquires  a 
harmonious  odor  only  by  long  storing. 

It  would,  therefore,  be  advisable  for  the  manufacturer  who 
works  with  potato  alcohol  not  to  use  the  highly  rectified  pro- 
duct, but  a  mixture  of  it  and  of  crude  spirits  containing  fusel 
oil,  the  vinegar  prepared  from  such  a  mixture  acquiring  a 
more  agreeable  odor  than  that  obtained  from  the  rectified  pro- 
duct. How  much  of  the  crude  spirits  has  to  be  used  can  only 
be  determined  by  experience,  but,  as  a  rule,  only  enough 
should  be  taken  to  assure  the  conversion  of  the  entire  quantity 
of  amyl  alcohol  present. 

The  fusel  oil  contained  in  spirits  of  wine  from  grain  consists 
largely  of  a  mixture  of  fatty  acids,  and  offers  far  greater  resist- 
ance to  oxidation  in  the  generators  than  amyl  alcohol.  The 
same  may  be  said  of  cenanthic  ether,  the  fusel  oil  of  brandy. 
In  working  with  alcoholic  liquid  prepared  with  a  large  quan- 
tity of  grain  spirits  containing  fusel  oil,  the  smell  of  un^ 
changed  fusel  oil  is  perceptible  in  the  vinegar  besides  the  odors 
of  the  products  of  its  decomposition.  With  the  use  of  small 
quantities  of  grain  spirits  containing  fusel  oil,  vinegar  possess- 
ing a  more  agreeable  odor  than  that  from  entirely  pure  spirits 
is  obtained. 


CHAPTER  XII. 

EXECUTION    OF    THE    WORK    IN    A    VINEGAR    FACTORY. 

WHEN  the  factory  is  in  proper  working  order  the  further 
execution  of  the  operation  is  very  simple,  it  being  only  neces- 
sary to  admit  at  stated  intervals  to  the  generators  a  previously 


EXECUTION    OF    THE    WORK    IN    A    VINEGAR    FACTORY.       117 

determined  quantity  of  alcoholic  liquid  and  to  collect  the 
vinegar  running  off.  With  the  operation  running  its  proper 
course,  attention  has  only  to  be  paid  to  the  maintenance  of  the 
correct  temperature  in  the  workroom  and  in  the  generators, 
the  chemical  process  proceeding  regularly  without  further 
assistance.  In  many  cases,  however,  deviations  from  the  reg- 
ular order  occur,  and  are  due  to  external  influences,  such  as 
changes  in  the  temperature  in  the  generators,  variations  in 
the  composition  of  the  alcoholic  liquid,  etc.  They  will  later 
on  be  discussed  in  a  special  chapter. 

The  capacity  of  a  factory  depends  on  the  number  of  gen- 
erators in  operation.  A  regularly  working  generator  is  sup- 
posed to  be  capable  of  daily  converting  3  liters  (3.16  quarts) 
of  absolute  alcohol,  and  this  quantity  will  be  taken  as  the  basis 
for  calculating  the  execution  of  the  operation.  If,  for  instance, 
vinegar  with  8  per  cent,  of  acetic  acid  is  to  be  manufactured, 
alcohol  of  8.8  per  cent,  by  weight  has  to  be  used,  and  to  pre- 
pare this,  3  liters  of  100  per  cent,  alcohol  have  to  be  reduced 
with  water,  so  that,  according  to  Table  I,  the  fluid  shows  a 
specific  gravity  of  0.9858  at  59°  F.  According  to  Table  III, 
8.98  liters  of  water  have  to  be  added  to  every  liter  of  100  per 
cent,  alcohol  to  obtain  spirits  of  wine  of  8.8  per  cent,  by 
weight ;  hence  3  liters  have  to  be  compounded  with  2G.94 
liters  of  water  (according  to  Table  III,  alcohol  with  90  per 
cent,  by  volume  of  alcohol  contains  11.80  per  cent,  by  volume 
of  water,  80  per  cent,  alcohol  22.83,  etc.,  which  has  to  be 
taken  into  consideration  in  making  the  dilution). 

According  to  Table  III,  the  contraction  in  this  case  amounts 
to  0.799  part  by  volume  for  every  100  parts  by  volume  of  the 
fluid.  Hence  the  3  liters  of  100  per  cent,  alcohol  yield,  when 
diluted  to  spirits  of  wine  of  8.8  per  cent,  by  weight,  26.94  +  3 
=  29.94  liters  of  fluid.  Actually  the  quantity  is  somewhat 
smaller,  as  in  mixing  alcohol  with  water  a  decrease  in  vol- 
ume takes  place.  If  the  alcoholic  liquid  is  to  contain  10  per 
cent,  each  of  vinegar  and  beer,  the  quantity  of  fluid  is  as 
follows : — 


118  MANUFACTURE    OF    VINEGAR. 

Dilute  spirits  of  wine  ........     29.94  litres. 

Vinegar  with  8  per  cent,  acetic  acid     .....       2.994    " 

Beer 2.994    " 

35.928 

Hence  the  quantity  to  be  worked  in  a  generator  in  the  course 
of  a  day  amounts  to  35.928  liters,  or  taking  into  account  the 
quantity  of  alcohol  (about  90  grammes  or  3.17  ozs.)  contained 
in  the  beer,  to  about  36  liters.  This  quantity  has  to  be  divided 
among  the  separate  pourings  so  that  in  a  working  time  of  15 
hours,  2.4  liters  would  have  to  be  poured  every  hour.  How- 
ever, by  this  method,  too  much  alcohol  would,  on  the  one 
hand,  be  lost  by  evaporation,  and,  on  the  other,  the  work  of 
the  generators  would  be  comparatively  slow,  since,  as  is  well 
known,  the  conversion  into  acetic  acid  is  effected  with  greater 
rapidity  when  the  alcoholic  liquid  contains  less  alcohol. 
Hence  it  is  advisable  to  use  in  the  commencement  of  the  oper- 
ation a  fluid  which  contains  only  about  one-half  or  two-thirds 
of  the  total  quantity  of  alcohol,  and  to  add  a  corresponding 
quantity  of  strong  alcohol  to  every  fresh  pouring. 

When  all  the  alcohol  has  been  converted  into  acetic  acid, 
the  vinegar  ferment,  as  previously  mentioned,  commences^with 
great  energy  to  oxidize  the  latter  to  carbonic  acid  and  water, 
and  hence  the  quantity  of  spirits  of  wine  added  to  the  alcoholic 
liquid  must  be  sufficiently  large  for  the  vinegar  running  off  to 
contain  always  a  minute  quantity  of  it. 

Much  has  been  written  about  this  gradual  strengthening  of 
the  alcoholic  liquid  with  alcohol,  and  explicit  directions  are 
given  as  to  the  original  composition  of  the  alcoholic  liquid,  as 
well  as  to  how  much,  how  often,  and  when  the  alcohol  is  to  be 
added.  These  directions  may  have  proved  useful  in  many 
cases,  but  local  conditions  exert  too  great  an  influence  upon 
the  process  of  manufacture  for  them  to  be  of  general  value. 
Besides  the  content  of  alcohol  in  the  alcoholic  liquid,  the  size 
of  the  generators,  the  strength  of  the  draught  in  them,  the 
temperature  prevailing  in  the  workroom  and  in  the  interior  of 
the  generators,  are  factors  which  must  be  taken  into  consider- 


EXECUTION    OF    THE    WORK    IN    A    VINEGAR    FACTORY.       119 

ation  in  determining  on  a  plan  of  operation  actually  adapted 
to  existing  conditions. 

The  size  of  the  generators  is,  of  course,  fixed  once  for  all. 
In  a  proper  state  of  working  the  strength  of  the  current  of  air 
must  be  so  regulated  that  the  temperature  in  the  interior  of  the 
generators  is  only  about  4.5°  F.  higher  than  that  of  the  work- 
room, which  is  readily  accomplished  with  a  suitable  central 
heating  apparatus.  There  still  remains  the  determination  of 
the  most  favorable  proportion  of  the  content  of  alcohol  in  the 
alcoholic  liquid  to  be  first  used  and  its  gradual  strengthening 
by  the  addition  of  spirits  of  wine,  which  can  only  be  effected 
by  a  chemical  examination  of  the  fluid  running  off  from  the 
generators. 

This  chemical  examination  is  restricted  to  the  accurate  de- 
termination of  the  quantity  of  acetic  acid  in  the  fluid  and  to 
that  of  the  alcohol  to  0.1  per  cent.  The  determination  of  the 
acetic  acid  is  effected  by  volumetric  analysis,  and  with  some 
experience  requires  four  to  five  minutes  for  its  execution.  For 
the  determination  of  the  alcohol  an  examination  with  the 
ebullioscope  suffices,  which  can  also  be  accomplished  in  four  to 
five  minutes.*  These  two  determinations,  which  every  vine- 
gar manufacturer  should  be  able  to  make,  are  the  only  means 
of  obtaining  an  accurate  control  of  the  working  of  the  factory, 
and  also  serve,  of  course,  for  settling  the  exact  plan  of  opera- 
tion from  the  start. 

If,  with  reference  to  the  example  given  above,  vinegar  with 
8  per  cent,  of  acetic  acid  is  to  be  prepared,  the  alcoholic  liquid 
must  contain  a  total  of  8.8  per  cent,  by  weight 'of  alcohol. 
Now  if  the  manufacture  is  commenced  with  an  alcoholic  liquid 
containing  the  total  quantity  of  water,  vinegar,  and  beer,  but, 
for  instance,  only  5  per  cent,  by  weight  of  alcohol,  the  follow- 
ing method  will  have  to  be  pursued  in  order  to  accurately 
determine  when  and  how  much  alcohol  has  to  be  added. 

The  first  portion  of  the  alcoholic  liquid  being  poured  into 

*  The  manner  of  executing  these  determinations  will  be  described  later  on. 


120  MANUFACTURE    OF    VINEGAR. 

the  generator,  the  fluid  running  off  is  tested  as  to  its  content 
of  acetic  acid  and  alcohol,  the  test  being  repeated  after  the 
second  and  each  successive  pourings.  Each  test  must  show  an 
increase  in  the  content  of  acetic  acid  and  a  decrease  in  that  of 
alcohol,  and  the  latter  must  finally  have  disappeared  so  far 
that  a  new  addition  of  alcohol  seems  to  be  in  order.  If  the 
test  after  the  third  pouring  shows  the  fluid  to  contain  only  0.3 
to  0.4  per  cent,  of  alcohol,  this  quantity  would  be  quickly  and 
completely  oxidized  in  the  fourth  pouring,  and  a  certain  quan- 
tity of  acetic  acid  be  at  the  same  time  destroyed.  Hence  it  is 
necessary  to  add,  for  instance,  2  per  cent,  by  weight  of  alcohol 
to  the  alcoholic  liquid  before  the  fourth  pouring.  When  this 
2  +  0.3  or  2  -f-  0.4  per  cent,  of  alcohol,  which  the  alcoholic 
liquid  now  contains,  is  again  reduced,  after  the  sixth  or 
seventh  pouring,  to  0.3  or  0.4  per  cent.,  the  last  addition  of 
1.8  per  cent,  of  alcohol  is  made,  the  total  quantity  of  alcohol, 
5  +  2  +  1.8  =  8.8  per  cent,  having  now  been  used. 

When,  after  a  certain  number  of  pourings,  a  test  of  the  fluid 
running  off  shows  a  content  of  8  per  cent,  of  acetic  acid  and 
only  0.1  or  0.2  per  cent,  of  alcohol  (a  small  remnant  of  alcohol 
should  always  be  present)  the  process  is  considered  as  finished, 
and  a  further  pouring  into  the  generator  would  not  only  be 
useless  labor,  but  contrary  to  the  end.  in  view,  since,  after  the 
complete  oxidation  of  the  last  remnants  of  alcohol,  that  of 
acetic  acid  would  immediately  commence,  and  weaker  vinegar 
would  be  obtained  after  each  pouring. 

If  a  generator  works  up  the  quantity  of  alcoholic  liquid  in- 
tended for  12  or  15  hours  in  10  or  12  hours,  it  is  more  proper, 
on  account  of  the  diminished  loss  by  evaporation,  to  induce 
slower  work  by  decreasing  the  draught  of  air  in  order  to 
maintain  the  rule  that  a  generator  has  to  work  up  3  liters  of 
absolute  alcohol  in  the  working  time  of  a  day. 

After  controlling  for  several  days  the  work  of  a  generator, 
by  examining  the  products  as  to  their  contents  of  acetic  acid 
and  alcohol,  the  plan  of  operation  resolves  itself  from  the 
results  of  these  tests,  since  then  it  is  accurately  known  after 


EXECUTION    OF    THE    WORK    IN    A    VINEGAR    FACTORY.       121 

how  many  pourings  of  an  alcoholic  liquid  of  known  composi- 
tion an  addition  of  alcohol  is  required  ;  further,  after  how  many 
pourings  a  finished  product  is  present,  so  that  directions  for 
the  progress  of  the  operation  can  be  given  to  the  workmen  ac- 
cording to  time  and  quantities.  The  normal  working  of  the 
generators  can  always  be  controlled  by  from  time  to  time  re- 
peating the  test  of  the  products. 

Now,  suppose  the  work  in  a  newly  arranged  factory  having 
reached  the  point  at  which  acetification  is  complete,  the  actual 
production,  according  to  the  old  method,  will  be  gradually 
commenced  by  pouring  in  alcoholic  liquid  of  corresponding 
concentration. 

The  shavings  of  the  generator  having  been  saturated  with 
acetifying  vinegar,  the  latter  is  partially  replaced  by  the  fluid 
poured  in,  and  as  much  as  is  expelled  runs  off.  If  the  gener- 
ator should  at  once  commence  to  work  regularly,  the  tempera- 
ture in  its  interior  would  be  observed  to  rise,  though  it  would 
at  first  be  impossible  to  establish  a  change  in  the  composition 
of  the  fluid  running  off.  Slight  variations  in  the  content  of 
acetic  acid  and  a  small  percentage  of  alcohol  could  be  deter- 
mined in  the  fluid  only  after  the  acetifying  vinegar  originally 
present  has  been  entirely  expelled  by  a  series  of  pourings. 

With  the  progress  in  the  manufacture  of  vinegar,  it  became 
customary  to  produce  the  strongest  vinegar  possible,  the  so- 
called  triple  vinegar,  with  about  12  per  cent,  of  acetic  acid. 
On  account  of  its  greater  commercial  value,  this  article  could 
be  sent  greater  distances,  the  consumer  reducing  it  to  a  weaker 
product  by  the  addition  of  water. 

To  prepare  directly  vinegar  with  such  a  high  percentage  of 
acetic  acid,  it  would,  however,  be  necessary  to  acetify  all  the 
generators  with  vinegar  of  the  same  strength,  and  to  use  alco- 
holic liquid  very  rich  in  alcohol.  By  this  method  the  losses  of 
alcohol  by  evaporation,  and  also  of  acetic'acid,  would,  however, 
be  so  great  as  to  make  the  product  too  expensive.  Further- 
more, the  work  would  require  most  careful  and  constant  atten- 
tion on  account  of  the  difficulty  with  which  oxidation  takes 


122  MANUFACTURE    OF    VINEGAR. 

place  in  alcoholic  liquid  containing  much  acetic  acid,  and  it 
might  only  too  readily  happen  that  the  generators  suddenly 
worked  with  less  vigor,  i.  e.,  that  the  content  of  acetic  acid  in 
the  vinegar  running  off  would  decrease,  and  the  quantity  of 
alcohol  remaining  unchanged  correspondingly  increase. 

On  account  of  these  difficulties,  it  has  become  customary  to 
charge  the  greater  number  of  generators  with  alcoholic  liquid 
yielding  the  so-called  double  vinegar  with  about  8  per  cent,  of 
acetic  acid,  and  to  work  this  vinegar  with  the  addition  of  the 
required  quantity  of  strong  spirits  of  wine  in  a  number  of 
generators,  which,  of  course,  must  be  acetified  with  12  per 
cent,  vinegar. 

It  will  be  readily  understood  that  the  employment  of  this 
method  is  not  only  advantageous  for  the  production  of  vinegar 
with  the  highest  attainable  content  of  acetic  acid,  but  also  for 
general  purposes.  Passing  the  alcoholic  liquid  but  once 
through  the  generators  does  not  suffice,  even  for  vinegar  with 
only  5  to  6  per  cent,  of  acetic  acid,  an  examination  always 
showing  a  considerable  quantity,  J  per  cent,  and  more,  of  un- 
converted alcohol  in  the  vinegar  running  off.  The  conversion 
of  alcoholic  liquid  with  a  small  content  of  alcohol  into  vinegar 
by  one  pouring  can,  to  be  sure,  be  accomplished,  but  it  neces- 
sitates the  use  of  very  tall  generators  and  a  constant  struggle 
with  difficulties  on  account  of  the  irregular  draught  of  air, 
caused  by  the  packing  together  of  the  shavings. 

Group  System. — Theoretically,  as  well  as  practically,  the 
group  system  may  be  considered  as  the  perfection  of  the  quick 
process.  The  principle  of  the  operation  consists  in  the  divi- 
sion of  the  generators  into  two  or  three  groups,  each  group 
preparing  vinegar  of  determined  strength.  In  factories  which 
do  not  produce  vinegar  of  the  greatest  attainable  strength  (12 
per  cent,  vinegar),  but  only  double  vinegar  with  about  8  per 
cent,  of  acetic  acid,  two  groups  might  suffice.  The  manufac- 
ture of  a  product  of  the  greatest  attainable  strength  being, 
however,  advisable  in  most  cases,  it  is  recommended  to  ar- 
range the  factory  for  continuous  work  with  three  groups  of 
generators. 


EXECUTION    OF    THE    WORK    IN    A    VINEGAR    FACTORY.       123 

For  this  purpose  the  number  of  generators  must  be  divisible 
by  three;  Hence  3,  6,  9,  12,  etc.,  generators  have  to  be  pro- 
vided, of  which  1,  2,  3,  4,  etc.,  form  one  group,  so  that,  for  in- 
stance, in  a  factory  working  with  24  generators  belonging  to 
one  group  with  the  same  number,  we  have  groups  I,  II  and 
III,  and  in  acetifying  and  operating,  the  generators  belonging 
to  one  group  are  treated  in  the  same  manner. 

For  the  preparation  of  the  strongest  vinegar  (12  per  cent.) 
the  generators  belonging  to  group  I  can,  for  instance,  be  acet- 
ified with  vinegar  of  6  per  cent,  acetic  acid,  those  of  group  II 
with  9  per  cent,  vinegar,  and  those  of  group  III  with  12  per 
•cent,  vinegar.  The  process  of  operation  is  then  as  follows  : — 

Group  I'.  The  generators  belonging  to  this  group  are 
charged  with  an  alcoholic  liquid  which  yields  vinegar 
with  a  content  of  6  per  cent,  acetic  acid,  and  the  fluid 
running  off  is  poured  back  into  the  generators  until  a 
test  shows  the  alcohol,  with  the  exception  of  a  small 
remnant,  to  have  been  converted  into  acetic  acid.  To 
this  vinegar  is  then  added  sufficient  strong  alcohol  to 
form  an  alcoholic  liquid  which  will  yield  9  per  cent, 
vinegar. 

Group  II.  The  alcoholic  liquid  for  9  per  cent,  vinegar- is 
poured  into  the  generators  belonging  to  group  II,  the 
pourings  being  repeated  until  all  but  a  very  small  quan- 
tity of  the  alcohol  is  oxidized.  The  vinegar  running 
off  is  again  compounded  with  sufficient  alcohol  to  form 
alcoholic  liquid  for  12  per  cent,  vinegar,  and  is  brought 
into 

Group  III.  The  pourings  are  here  repeated  until  the  oxi- 
dation of  alcohol  is  nearly  complete.  The  finished 
product  is  then  stored  or  clarified. 

As  will  be  seen  from  the  above,  in  operating  according  to 
the  group  system,  the  entire  factory  is,  so  to  say,  divided  into 
three  factories,  I,  II,  and  III,  of  which  I  produces  vinegar  of 
6  per  cent.,  II  vinegar  of  9  per  cent.,  and  III  vinegar  of  12 


124  MANUFACTURE    OF    VINEGAR. 

per  cent.  The  product  of  I,  after  having  been  converted  by  a 
suitable  addition  of  alcohol  into  alcoholic  liquid  adapted  for 
the  preparation  of  9  per  cent,  vinegar,  is  directly  used  for 
charging  the  generators  of  group  II,  and  that  of  II  for  charg- 
ing III. 

The  generators  belonging  to  one  group  having  been  aceti- 
fied with  vinegar  of  the  same  strength,  the  fluid  running  off 
from  one  generator  need  not  necessarily  be  returned  to  it. 
The  work  can,  therefore,  be  simplified  by  conducting  the  fluid, 
running  off  from  all  the  generators  by  means  of  a  suitable 
pipe-system  into  a  common  receiver  instead  of  allowing  the 
fluid,  which  has  passed  through  a  generator,  to  collect  under 
a  false  bottom  and  then  drawing  it  off  and  returning  it  to  the 
same  generator.  If,  for  instance,  8  generators  belong  to  one 
group  and  3  litres  have  at  the  same  time  been  poured  into 
each,  the  passage  of  the  liquid  through  all  the  generators  will 
be  shown  by  a  measuring  scale  placed  in  the  common  receiver, 
indicating  that  the  latter  contains  3x8=24  litres. 

The  samples  for  determining  the  content  of  acetic  acid  and 
alcohol  are  taken  from  the  common  receiver,  and  the  latter 
also  serves  for  the  conversion  of  the  vinegar,  after  it  has  ac- 
quired the  percentage  of  acid  attainable  in  that  group,  into 
stronger  alcoholic  liquid  by  the  addition  of  alcohol.  In  order 
to  effect  an  intimate  mixture,  and  at  the  same  time  prevent 
the  vinegar  ferment  floating  in  the  fluid  from  suffering  injury 
by  coming  in  contact  with  the  highly  concentrated  spirits  of 
wine,  the  required  quantity  of  the  latter  is  introduced  in  a 
thin  jet  and  with  constant  stirring. 

In  many  factories  it  is  customary  from  time  to  time  to  alter- 
nate with  the  pourings  in  the  groups  or  "  to  cross  the  genera- 
tors." By  this  "  crossing  "  the  alcoholic  liquid,  which,  accord- 
ing to  the  above  method,  would,  for  instance,  pass  from  group 
II  to  group  III,  is  poured  into  group  I,  so  that  after  some  time 
the  generators  of  this  group  are  converted  into  generators  of 
group  III  (with  12  per  cent,  acid),  and  group  III  becomes 
group  I,  it  now  containing  the  weakest  alcoholic  liquid  (with  6 


EXECUTION    OF    THE    WORK    IN    A    VINEGAR    FACTORY.       125 

per  cent.  acid).  Crossing,  however,  cannot  be  recommended, 
because  a  sudden  change  in  the  constitution  of  the  nourishing 
fluid  always  exerts  an  injurious  influence  upon  the  propaga- 
tion of  the  vinegar  ferment. 

Recourse  to  crossing  is  most  frequently  had  for  the  purpose 
of  "  strengthening  "  the  vinegar  ferment  by  working  weaker 
alcoholic  liquid  in  the  generators  of  one  group— generally  that 
which  yields  the  strongest  vinegar — when  their  activity  dimin- 
ishes. This  strengthening  of  the  ferment  can,  however,  be 
effected  in  a  more  simple  and  suitable  manner  by  diminishing 
the  quantity  of  alcoholic  liquid  poured  in  at  one  time  and  by 
increasing  the  draught  of  air,  and  the  consequent  change  of 
temperature  in  the  generators,  so  that  the  principal  reasons  for 
"  crossing  the  generators  "  (which  many  manufacturers  consider 
indispensable)  have  no  force. 

Group  System  with  Automatic  Contrivances.  If  the  pourings 
of  the  alcoholic  liquid  are  to  be  effected  at  determined  inter- 
vals by  an  automatic  contrivance,  the  group  system  as  de- 
scribed on  p.  122  et  seq.  should  be  used.  The  operation  of 
such  a  factory  is  very  simple.  As  seen  from  the  description 
of  the  arrangement,  the  generators  are  divided  into  three 
groups,  I,  II,  and  III.  Besides  the  generators  each  group  must 
be  provided  with  a  reservoir,  which  may  be  designated  R,  and 
a  collecting  vessel  C.  (The  other  component  parts,  distribu- 
ting arrangements  and  conduit,  can  here  be  left  out  of  con- 
sideration.) 

For  the  production  of  12  per  cent,  vinegar  in  such  a  factory 
it  is  the  best  so  to  prepare  the  alcoholic  liquid  for  the  several 
groups  that 

Group  I  contains  alcoholic 

liquid  with  .  .  .  .  6  p.  c.  acetic  acid  and  6.5  to  6.6  p.  c.  alcohol. 

Group  II  contains  alcoholic 

liquid  with  ....  9  "  +3.2  to  3. 3 

Group  III  contains  alco- 
holic liquid  with  .  .  .  12  "  "  +3.2  to  3.3 


126  MANUFACTURE    OF    VINEGAR. 

Group  I  having  been  acetified  with  6  per  cent,  vinegar, 
group  II  with  9  per  cent,  vinegar,  and  group  III  with  12  per 
cent,  vinegar,  the  fluid  running  off  from  group  I,  after  being 
compounded  with  3.2  to  3.3  per  cent,  of  alcohol,  is  used  in 
group  II  as  alcoholic  liquid  for  9  per  cent,  vinegar,  and  yields 
9  per  cent,  vinegar,  which  after  being  again  compounded  with 
3.2  to  3.3  per  cent,  of  alcohol,  yields  12  per  cent,  vinegar  after 
having  passed  through  group  III. 

The  uninterrupted  working  of  the  generators  constituting 
one  of  the  principal  advantages  of  the  automatic  system,  it  is 
advisable  to  regulate  the  automatic  contrivance  so  that  but  a 
small  quantity  of  alcoholic  liquid  be  at  one  time  poured  out, 
and  to  fix  the  intervals  between  two  pourings  so  that  the  sec- 
ond pouring  takes  place  after  about  one-half  of  the  first  has 
run  off.  Under  these  conditions  there  will  be  in  the  lower 
half  of  the  generator  an  alcoholic  liquid  in  which  the  alcohol 
is  nearly  as  much  oxidized  as  it  can  be  by  one  passage  through 
the  generator,  while  in  the  upper  half  will  be  fresh  alcoholic 
liquid  in  which  oxidation  is  continued  without  interruption. 
A  further  advantage  obtained  by  this  is  that  a  generator  will 
yield  quantitatively  more  than  one  working  only  15  to  16 
hours ;  further,  the  conditions  of  temperature  in  the  interior 
of  the  generator  remain  always  the  same,  and  the  ferment  con- 
stantly finds  nutriment. 

The  alcoholic  liquid  for  group  I  is  pumped  into  the  reser- 
voir B^  and  passes  through  the  generators  of  group  I  into  the 
collecting  vessels  Cr  All  the  alcoholic  liquid  having  run  off 
from  RV  the  fluid  collected  in  Cv  after  having  been  tested  as 
to  its  content  of  acetic  acid,  is  for  the  second  time  pumped  in- 
to R!  and  passes  again  through  the  generators  of  group  I.  The 
automatic  contrivance  is  so  regulated  that  the  alcoholic  liquid, 
after  being  twice  poured  in,  contains  but  a  very  small  remnant 
of  alcohol. 

To  the  vinegar  of  6  per  cent,  collected  in  Gl  is  now  added 
3.2  to  3.3  per  cent,  by  weight  of  alcohol,  best  in  the  form  of 
80  to  90  per  cent,  spirits  of  wine.  The  resulting  stronger  alco- 


EXECUTION    OP    THE    WORK    IN    A    VINEGAR    FACTORY.       127 

holic  liquid  is  at  once  pumped  into  J?2,  and  passing  through 
the  generators  of  group  II  reaches  the  collection  vessel  C2.  It 
is  then  tested,  pumped  back  into  .7?2,  and  again  collected  in  C2. 
If  it  now  shows  the  required  strength,  it  is  mixed  with  the 
second  portion  of  3.2  to  3.3  per  cent,  by  weight  of  alcohol  and 
is  pumped  into  J?3,  and  after  passing  twice  through  the  gene- 
rators collects  as  finished  vinegar  in  (73. 

It  will  be  seen  from  the  above  description  of  the  process  that 
in  making  the  tests,  the  product  of  all  the  generators  of  one 
group  is  treated  as  a  whole.  A  disturbance  may,  however, 
occur  in  either  one  of  the  generators,  and  it  would  take  consid- 
erable time  before  its  existence  would  be  detected  by  a  change 
in  the  constitution  of  the  entire  product.  The  thermometer 
with  which  each  generator  is  provided  is,  however,  a  reliable 
guide  as  to  the  activity  of  the  latter,  and  if  it  shows  in  one  of 
them  a  temperature  varying  from  37°  to  49°  F.  from  that  pre- 
vailing in  the  others,  it  is  a  sure  sign  of  the  respective  generator 
not  working  in  the  same  manner  as  the  others,  and  the  product 
running  off  from  it  should  be  tested  by  itself  as  to  its  content 
of  acetic  acid  and  alcohol. 

Generally  it  will  contain  either  no  alcohol  or  very  much  of  it. 
In  the  first  case  the  temperature  of  the  respective  generator  is 
higher  than  that  prevailing  in  the  others,  and  its  activity  has 
to  be  moderated  by  decreasing  the  admission  of  air;  in  the 
other  case,  the  generator  works  too  sluggishly,  and  the  differ- 
ence is  sought  to  be  equalized  by  increasing  the  current  of  air 
or  giving  a  few  pourings  of  somewhat  warmer  alcoholic  liquid. 
With  a  good  heating  apparatus  producing  a  uniform  tempera- 
ture in  the  workroom  such  disturbances  will,  however,  but 
seldom  happen,  and  by  the  use  of  the  above  means  the  normal 
working  of  the  generators  can  be  restored. 


128  MANUFACTURE    OF    VINEGAR. 


CHAPTER  XIII. 

DISTURBING    INFLUENCES    IN    THE    MANUFACTURE    OF    VINEGAR. 

IN  no  other  industry  based  upon  the  process  of  fermentation 
are  irregularities  and  disturbances  of  such  frequent  occurrence 
as  in  the  manufacture  of  vinegar.  Besides  the  nourishing  sub- 
stances dissolved  in  the  fluid  and  free  oxygen,  the  vinegar  fer- 
ment requires  a  certain  temperature  for  its  abundant  propaga- 
tion, by  which  alone  large  quantities  of  alcohol  can  in  a  short 
time  be  converted  into  acetic  acid.  By  exercising  the  neces- 
sary care  for  the  fulfillment  of  these  conditions  serious  dis- 
turbances can  be  entirely  avoided,  and  the  slighter  ones  due 
to  insufficient  acetic  fermentation  of  the  ferment  readily  re- 
removed. 

As  regards-  the  nourishing  substances  of  the  ferment,  irregu- 
larities can  actually  occur  only  in  working  continuously  with 
an  alcoholic  liquid  composed  exclusively  of  water  and  alcohol. 
In  such  alcoholic  liquid  the  nitrogenous  substances  necessary 
for  the  nutriment  of  the  ferment  are  wanting,  nor  are  the  phos- 
phates present  in  sufficient  quantity.  The  consequences  are 
the  same  as  in  every  insufficiently  nourished  ferment-organism  • 
The  fermenting  activity  suddenly  diminishes,  propagation  pro- 
ceeds sluggishly  and  ceases  entirely  if  abundant  nutriment  is 
not  introduced.  Hence  it  may  happen  that  from  a  generator 
containing  alcoholic  liquid  composed  only  of  water,  alcohol, 
and  vinegar,  the  greater  portion  of  the  alcohol  suddenly  runs 
off  unchanged,  the  temperature  in  the  interior  of  the  generator 
at  the  same  time  falling,  and  the  draught  of  air  ceasing  soon 
afterwards.  When  these  phenomena  appear  it  should  first  be 
ascertained  whether  the  disturbance  is  not  due  to  too  slight  a 
current  of  air.  For  this  purpose  the  draught-holes  are  entirely 
opened,  and  if  the  temperature  rises  the  generator  gradually 
resumes  its  normal  working.  If,  however,  no  improvement  is 
observed,  the  disturbance  is  due  to  defective  nutriment,  and  the 
composition  of  the  alcoholic  liquid  has  to  be  changed,  which  is 


DISTURBING    INFLUENCES    IN    MANUFACTURE.  129 

best  effected  by  the  addition  of  a  few  per  cent,  of  beer  or  of 
fermented  alcoholic  mash,  either  one  of  them  containing  a  suffi- 
cient quantity  of  phosphates  and  albuminous  substances.  The 
use  of  sweet  beer  wort  or  malt  extract  has  also  been  highly 
recommended  for  ''strengthening  weak-working  generators." 
These  substances  also  furnish  albuminous  bodies  and  phos- 
phates to  the  alcoholic  liquid,  but  they  also  contain  maltose  and 
dextrin,  and  as  it  has  not  yet  been  ascertained  whether  the 
latter  and  the  carbohydrates  in  general  can  be  consumed  and 
digested  by  the  ferment,  they  possibly  may  pass  unchanged 
into  the  vinegar.  Honey  and  glucose  are  also  sometimes  used 
for  strengthening  purposes,  but  while  the  former  might  be 
useful  on  account  of  the  abundance  of  salts  and  nitrogenous 
substances  it  contains,  no  substances  of  any  value  to  the  fer- 
ment are  present  in  the  latter.  At  any  rate  the  addition  of 
beer,  mash,  or  malt  extract  is  to  be  preferred. 

An  addition  of  phosphate  to  the  alcoholic  liquid  is  also 
claimed  to  produce  a  favorable  effect  upon  the  propagation  of 
the  ferment.  Commercial  phosphoric  acid  is  dissolved  in 
water  and  the  solution  neutralized  with  potassium,  a  solution 
of  potassium  phosphate  being  in  this  manner  obtained.  The 
vinegar  ferment  being  very  sensitive  towards  this  salt,  a  very 
small  quantity  of  the  solution,  about  10ouo  of  the  weight  of  the 
alcoholic  fluid  may  be  added.  The  experiment  must,  how- 
ever, be  made  very  cautiously,  and  the  effect  upon  the  working 
of  the  generator  carefully  noted. 

Disturbances  ascribable  to  the  quantity  of  newly  formed  Acetic 
Acid.  Under  proper  working  conditions  the  alcoholic  liquid 
brought  into  the  generators  should  be  completely  converted 
into  vinegar,  and  theoretically,  the  product  running  off  show 
the  same  strength  a?  the  vinegar  used  for  acetification.  Act- 
ually there  are,  however,  slight  variations  not  exceeding  a  few 
tenths  of  one  per  cent.  Should  greater  differences  appear,  a 
disturbance  actually  exists  and  may  show  itself  in  various  ways. 
The  generator  may  work  too  feebly  or  too  vigorously.  In  the 
first  case  the  content  of  acetic  acid  in  the  fluid  running  off  de- 
9 


130  MANUFACTURE    OF    VINEGAR. 

creases  considerably,  while  that  of  alcohol  increases.  The 
process  of  the  formation  of  vinegar  is,  so  to  say,  only  half 
carried  through,  a  great  portion  of  the  alcohol  being  converted, 
not  into  acetic  acid,  but  into  aldehyde.  The  greater  portion 
of  this  combination  is  lost  to  the  manufacturer  on  account  of 
its  low  boiling  point  (71.6°  F.),  it  escaping  in  the  form  of  vapor, 
the  stupefying  odor  of  which  when  noticed  in  the  air  of  the 
workroom  is  accepted  by  all  manufacturers  as  indicative  of  a 
disturbance  in  the  regular  working  of  the  generators.  This 
odor,  however,  becomes  perceptible  only  after  the  disturbance 
has  continued  for  some  time,  with  the  loss  of  a  considerable 
quantity  of  alcohol.  Hence  the  control  of  the  working  of  the 
generators  by  a  frequent  determination  of  the  acid  becomes 
necessary.  Repeated  observations  of  the  thermometer  also 
furnish  valuable  hints  about  the  progress  of  the  chemical  pro- 
cess. The  temperature  in  this  case  remains  only  for  a  short 
time  unchanged  and  soon  falls,  far  less  heat  being  liberated  in 
the  mere  conversion  of  alcohol  into  aldehyde  than  when  oxi- 
dation progresses  to  the  formation  of  vinegar.  These  phe-, 
nomena  are  indicative  of  the  generator  not  being  able  to  master 
the  alcoholic  liquid  introduced,  and  may  be  due  to  the  pourings 
being  too  large,  or  the  temperature  of  the  alcoholic  liquid 
poured  in  being  too  low,  or  finally  to  an  insufficient  draught 
of  air. 

To  restore  the  generator  to  a  proper  state  of  working,  it  is 
best  to  try  first  the  effect  of  smaller  pourings,  and  then  an  in- 
creased draught  of  air.  If  the  disturbance  was  due  to  an  in- 
sufficient draught  of  air,  the  temperature  soon  rises  and  the 
generator  will  be  able  to  work  up  the  regular  quantity  of  alco- 
holic liquid.  By  the  use  of  alcoholic  liquid  of  a  somewhat 
higher  temperature  the  restoration  of  the  normal  conditions 
can  be  accelerated. 

A  decrease  in  the  content  of  acetic  acid  in  the  fluid  running 
off  from  the  generators  without  the  presence  of  alcohol  being 
shown,  indicates  a  too  vigorous  process  of  oxidation,  the  alco- 
hol being  not  only  oxidized  to  acetic  acid,  but  the  latter  further 


DISTURBING    INFLUENCES    IN    MANUFACTURE.  131 

into  carbonic  acid  and  water.  The  temperature  in  the  interior 
of  the  generators  rises  considerably,  about  45°  F.,  above  that 
of  the  workroom. 

In  this  case  the  restoration  of  the  respective  generator  to  a 
proper  state  of  working  is  not  difficult  and  can  be  effected  in 
two  ways,  either  by  considerably  decreasing  the  ventilation  ot 
the  generator,  or  by  pouring  in  a  larger  quantity  of  alcoholic 
liquid  than  previously  used. 

Heating  of  the  generators  is  generally  due  to  faulty  con- 
struction. Generators  of  large  dimensions,  as  a  rule,  become 
too  warm  much  easier  than  smaller  ones,  the  phenomenon  also 
appearing  more  frequently  in  summer  than  in  winter;  and 
"  too  warm  "  being  just  as  injurious  to  the  efficacy  of  the  gen- 
erators as  "  too  cool,"  they  must,  during  the  warm  season  of 
the  year,  be  as  carefully  protected  against  too  high  a  tempera- 
ture as  against  cooling  during  the  cold  season.  This  is  effected, 
on  the  one  hand,  by  a  suitable  ventilation  of  the  workroom 
during  the  night,  and,  on  the  other,  by  the  use  of  alcoholic 
liquid  of  a  somewhat  lower  temperature  during  the  hottest 
season  of  the  year.  Moreover,  disturbances  from  too  high  a 
temperature  of  the  exterior  air  need  only  be  feared  in  coun- 
tries with  a  very  warm  climate. 

It  has  been  frequently  proposed  to  counteract  a  too  vigorous 
activity  of  the  generators  by  the  addition  of  a  little  oil  of  cloves 
or  salicylic  acid  which  have  the  property  of  checking  fermenta- 
tion. Salicylic  acid,  especially,,  is  an  excellent  corrective  for 
the  faulty  working  of  a  generator.  It  has  to  be  used,  however, 
with  great  caution  and  only  be  added  by  the  TTOOITO  °f  the 
weight  of  the  alcoholic  liquid,  and  just  in  sufficient  quantity 
to  attain  the  desired  result.  A  large  amount  is  injurious  to 
the  ferment  and  might  kill  it. 

"  Sliming  "  of  the  Shavings  in  Generators. — This  disturb- 
ance sometimes  occurs  in  a  vinegar  plant,  and  its  progress  gen- 
erally ends  in  throwing  the  entire  operation  into  complete 
disorder  so  that  finally  no  more  vinegar  can  be  produced. 
After  fruitless  experiments  nothing  remains  but  to  empty  the 


132  MANUFACTURE    OF    VINEGAR. 

generator,  wash  the  shavings  with  hot  water  and,  after  drying 
and  steeping  them  in  hot  vinegar,  return  them  to  the  gen- 
erator. 

Sliming  may  be  due  to  infection  by  foreign  bacteria  and 
fungi,  as  well  as  to  super-oxidation  and  the  accumulation  of 
larger  quantites  of  alcohol  in  the  shavings  which  affects  the 
bacteria  to  such  an  extent  that  they  have  no  longer  the  power 
of  forming  acetic  acid  or  only  very  sinall  quantities  of  it,  but 
only  aldehyde,  the  intermediate  product  between  alcohol  and 
acetic  acid. 

The  trouble  begins  to  show  itself  by  the  generators  commenc- 
ing to  work  irregularly.  While  formerly  a  certain  quantity  of 
alcohol  was  after  a  fixed  number  of  pourings  converted  into 
acetic  acid,  a  large  number  of  pourings  are.  now  required  to 
attain  the  same  result.  The  generators  work  slower  and  the 
heat  in  their  interior  decreases.  By  heating  the  workroom 
more  strongly  only  a  temporary  improvement  is  brought  about, 
and  the  production  of  the  generators  becomes  less  and  less,  and, 
finally,  so  low  that  work  has  to  be  interrupted.  When  the 
disturbance  has  progressed  thus  far  a  disagreeable  musty,  in- 
stead of  the  characteristic  acid  odor,  is  perceived  in  the  work- 
room. By  allowing  one  of  the  faulty  working  generators  to 
stand  for  a  few  days  without  charging  it  with  alcoholic  liquid, 
the  temperature  in  the  interior  may  rise  considerably  and  pro- 
ducts of  putrefaction  be  developed  to  such  an  extent  as  to 
taint  the  air  of  the  workroom. 

Long  before  this  phenomenon  becomes  apparent,  an  altera- 
tion takes  place  in  the  shavings.  A  shaving  taken  from  a 
normally  working  generator  has  the  ordinary  appearance  of 
wet  wood  ;  but  one  taken  from  a  generator  working  in  the 
above-mentioned  faulty  manner  is  coated  with  a  slimy  mass, 
which  is  somewhat  sticky,  and  can  be  drawn  into  short  threads. 
Viewed  under  the  microscope  this  slimy  coating  presents  a 
structureless  mass,  throughout  which  numerous  germs  of  vine- 
gar ferment  are  distributed  and  sometimes  the  vinegar  eels. 
Independently  of  the  presence  of  the  latter,  this  slimy  coating 


DISTURBING    INFLUENCES    IN    MANUFACTURE.  133 

presents  the  same  appearance  as  the  so-called  mother  of  vine- 
gar. By  placing  a  shaving  coated  with  slime  upright  in  a  shal- 
low dish,  and  filling  the  latter  f  the  height  of  the  shaving  with 
alcoholic  liquid,  the  previously  described  delicate  veil  of  vine- 
gar ferment  develops  upon  the  surface,  while  the  portion  of  the 
shaving  covered  by  the  fluid  is  surrounded  by  flakes  distin- 
guished by  nothing  from  mother  of  vinegar.  Hence  there  can 
scarcely  be  a  doubt  that  the  slimy  coating  actually  consists  of 
the  same  structure  to  which  the  term  mother  of  vinegar  (see 
p.  21)  has  been  applied,  and  in  searching  for  the  cause  of  the 
formation,  it  will  generally  be  found  to  be  due  to  conditions 
similar  to  those  which  give  rise  to  the  formation  of  the  latter. 
An  alcoholic  liquid  overly  rich  in  young  beer  containing  much 
albumen,  or  one  to  which  much  malt  extract  or  young  fruit- 
wine  has  been  added,  is  apt  to  give  rise  to  the  formation  of 
mother  of  vinegar  in  the  generators.  The  slimy  coating  thus 
formed  upon  the  shavings  envelops  the  vinegar  ferment  and 
prevents  its  immediate  contact  with  the  air ;  consequently  the 
alcoholic  liquid  does  not  encounter  as  much  ferment  as  is  re- 
quired for  the  complete  oxidation  of  the  alcohol,  and  the  gen- 
erators become  weaker.  This  decrease  in  the  production  is,  of 
course,  followed  by  a  lower  temperature  in  the  generators,  and 
consequently  by  a  decrease  in  the  propagation  of  the  ferment, 
these  unfavorable  conditions  finally  becoming  so  great  as  to 
bring  the  activity  of  the  generators  to  a  standstill. 

The  settlement  of  vinegar  eels  upon  the  surface  of  the  mother 
of  vinegar  has  no  connection  with  sliming.  Should,  however, 
large  masses  of  these  animalcules  happen  to  die  in  the  genera- 
tors for  want  of  air,  due  to  the  constantly  decreasing  draught, 
they  quickly  putrefy  on  account  of  the  high  temperature,  and 
give  rise  to  the  most  disagreable  odors. 

A  careful  manufacturer  will  observe  sliming  at  the  com- 
mencement of  the  evil,  when  it  can  be  remedied  without  much 
difficulty.  First  of  all,  the  composition  of  the  alcoholic  liquid 
must  be  changed  by  discontinuing  the  use  of  fluid  containing 
many  carbohydrates  and  albuminous  substances,  such  as 


134  MANUFACTURE    OF    VINEGAR. 

young  beer,  malt  extract,  young  fruit-wine,  it  being  best  to 
use  alcoholic  liquid  of  water,  vinegar,  and  alcohol  only  until 
the  generators  are  entirely  restored  to  a  normal  working 
condition.  The  activity  of  the  ferment  is  at  the  same  time 
increased  by  a  stronger  draught  of  air  in  the  generators  and 
by  raising  the  temperature  of  the  workroom.  In  a  few  days 
the  generators  will  be  again  in  a  proper  working  condition, 
which  is  recognized  by  the  normal  conversion  of  alcohol  into 
acetic  acid. 

If,  however,  the  evil    has    progressed    to  a  certain  extent 

FIG.  36. 


nothing  can  be  done  but  to  empty  the  generators.  Though 
considerable  labor  is  connected  with  this  operation,  there  is 
no  further  use  of  experimenting,  since  such  nonsensical  addi- 
tions as  beer-yeast,  tartar,  honey,  etc.,  which  have  been  pro- 
posed as  remedies,  only  accelerate  the  final  catastrophe — the 
entire  cessation  of  the  formation  of  vinegar.  Should  a  dis- 
turbance occur  which  cannot  be  accounted  for  by  defective 
nutriment  of  the  ferment,  want  of  air>  or  an  incorrect  state  of 
the  temperature,  the  condition  of  the  shavings  should  be  at 
once  examined  into,  and  if  they  show  the  first  stages  of  sliming 


DISTURBING    INFLUENCES    IN    MANUFACTURE. 


135 


the  evil  should,  if  possible,  be  remedied  by  changing  the  com- 
position of  the  alcoholic  liquid.  If  the  new  alcoholic  liquid 
contains  only  water,  vinegar,  and  alcohol,  sliming  cannot 
progress,  and  the  layers  of  slime  upon  the  shavings  will  in  a 
short  time  disappear,  they  being  partially  utilized  in  the  nu- 
triment of  the  ferment,  and  partially  mechanically  washed 
off  by  the  alcoholic  liquid  running  down. 

Disturbances  due  to  Vinegar  Eels.  In  many  factories  filamen- 
tous structures  scarcely  visible  to  the  naked  eye  will  frequently 
be  observed  in  the  vinegar.  When  viewed  under  the  micro- 

FIG.  37. 


scope  they  will  be  recognized  as  animalcules,  to  which  the 
term  vinegar  eel  (Anguilla  aceti)  has  been  applied  on  account 
of  their  form  slightly  resembling  that  of  an  eel.  Fig.  36 
shows  a  microscopical  picture  of  a  drop  of  vinegar  swarming 
with  vinegar  eeis  slightly  magnified,  and  Fig.  37  a  vinegar 
eel  greatly  magnified. 

The  animalcule  consists  of  a  cylindrical  body  running  to  a 
sharp  point.  The  mouth-opening  is  covered  with  small  knots ; 
the  throat  is  globular  and  passes  directly  into  the  long  intes- 
tinal tube.  The  eggs  are  placed  at  about  the  centre  of  the 


136  MANUFACTURE    OF    VINEGAR. 

body  in  two  tubes  which  unite  to  a  plainly  perceptible  aper- 
ture. The  average  length  of  the  female  is  0.0682  Paris  inch 
and  that  of  the  male  0.0486,  the  former  being  larger  than  the 
latter  in  proportion  of  1  :  1.3. 

Vinegar  eels  can  exist  in  dilute  alcohol  of  the  strength  used 
in  making  vinegar  as  well  as  in  dilute  acetic  acid.  In 
alcoholic  liquid  containing  much  alcohol  and  acetic  acid  they 
do  not  thrive  as  well  as  in  weak  liquid.  Their  part  in  the 
manufacture  ol  vinegar  is  under  .all  conditions  an  injurious 
one.  The  vinegar  ferment  can  only  carry  on  its  function 
correctly  when  vegetating  upon  the  surface  of  the  fluid  and  in 
contact  with  air.  The  vinegar  eel  being  an  air  breathing 
animal  always  seeks  the  surface,  and  in  an  alcoholic  liquid 
which  contains  it,  and  upon  whose  surface  an  abundance  of 
ferment  grows,  actual  combats  between  animalcule  and  fer- 
ment can  be  observed,  the  former  striving  to  force  the  latter, 
which  is  inimical  to  its  existence,  under  the  surface  and  thus 
render  it  harmless.  (Submerged  vinegar  ferment,  as  is  well 
known,  changes  its  conditions  of  existence  aud  becomes  mother 
of  vinegar.)  If  the  conditions  are  favorable  for  the  develop- 
ment of  the  animalcules,  the  latter  overcome  the  ferment  and 
submerge  it  so  that  it  can  continue  to  exist  only  as  mother  of 
vinegar,  and  consequently  the  process  of  the  formation  of 
vinegar  will  be  considerably  retarded.  Under  conditions 
favorable  to  the  development  of  the  ferment  the  reverse  is  the 
case.  The  ferment  floating  upon  the  fluid  consumes  nearly 
all  the  oxygen  contained  in  the  layer  of  air  immediately  above 
the  surface,  and  thus  deprives  the  animalcules  of  a  condition 
necessary  for  their  existence.  A  portion  of  them  die  and  fall 
to  the  bottom  of  the  vessel,  while  another  portion  of  them 
escape  to  the  sides  of  the  vessel  where  they  congregate  imme- 
diately above  the  surface  of  the  fluid  in  such  masses  as  to  form 
a  whitish  ring.  These  conditions  can  be  readily  induced  by 
pouring  vinegar  containing  a  large  number  of  vinegar  eels 
into  a  flat  glass  dish  and  adding  a  fluid  upon  which  vinegar 
ferment  has  been  artificially  cultivated.  In  a  few  hours  the 


DISTURBING    INFLUENCES    IN    MANUFACTURE.  137 

ferment  has  spread  over  the  entire  surface  and  the  animalcules 
form  the  above-mentioned  white  ring  on  the  sides  of  the  vessel. 
If  by  means  of  blotting  paper  the  veil  of  ferment  be  removed 
as  fast  as  it  propagates,  the  animalcules  soon  spread  over  the 
entire  fluid. 

From  the  above  explanation  it  is  evident  that  the  appearance 
of  vinegar  eels  in  large  masses  threatens  danger  to  the  regular 
working.  When  the  animalcules  reach  the  shavings  the  strug- 
gle for  existence  between  them  and  the  ferment  commences, 
and  their  struggling  to  dislodge  the  latter  may  be  the  first  cause 
of  the  formation  of  slimy  masses  of  mother  of  vinegar  upon 
the  shavings.  Since  the  vinegar  eels  consume  oxygen,  the  air 
in  the  generators  becomes  thereby  less  suitable  for  the  nourish- 
ment of  the  ferment,  and  consequently  the  generators  will  work 
feebly.  By  accelerating  the  draught  of  air  in  the  generators, 
which  is  generally  the  first  remedy  tried,  the  development  of 
the  ferment  may  again  become  so  vigorous  that  a  large  portion 
of  the  vinegar  eels  are  killed,  their  bodies  being  found  in  the 
vinegar  running  off.  The  dead  vinegar  eels  remaining  in  the 
generator,  however,  finally  putrefy  and  give  rise  to  the  pre- 
viously mentioned  disagreeable  odor.  The  processes  of  putre- 
faction being  also  effected  by  bacteria  capable  of  decomposing 
nearly  all  known  organic  combinations  (even  small  quantities 
of  such  strongly  antiseptic  bodies  as  salicylic  and  carbolic 
acids),  it  is  evident  that  vinegar  containing  vinegar  eels,  can- 
not possess  good  keeping  qualities  and  must  be  subjected  to  a 
special  treatment,  which  will  be  referred  to  later  on. 

Several  remedies  for  the  suppression  of  vinegar  eels  in  the 
generators  have  been  proposed,  one  of  them  consisting  of  the 
introduction  of  vapors  of  burning  sulphur,  i.  e.,  sulphurous 
acid.  Sulphurous  acid,  it  is  true,  kills  the  vinegar  eels,  but 
at  the  same  time,  the  vinegar  ferment,  and  if  small  remnants 
remain,  also  the  newly-introduced  ferment.  To  restore  a 
generator  thus  treated,  a  large  quantity  of  air  must  be  blown 
through  it,  which  will  remove  the  last  traces  of  sulphurous 
acid.  An  alcoholic  liquid  containing  much  living  ferment  is 
then  poured  in. 


138  MANUFACTURE    OF    VINEGAR. 

The  vinegar  ferment  can  for  many  hours  stand  the  exclusion 
of  oxygen  without  being  destroyed,  while  the  vinegar  eels  die 
in  a  short  time.  This  circumstance  can  be  utilized  for  the  de- 
struction of  the  animalcules  without  recourse  to  other  reme- 
dies. The  generator  having  first  been  brought  into  the  high- 
est state  of  activity  by  pouring  in  very  warm  alcoholic  liquid 
and  opening  all  the  draught-holes,  is  left  to  itself  for  6  or  8 
hours  after  closing  all  the  draught-holes.  The  ferment  in  a 
short  time  consumes  all  the  free  oxygen  in  the  generators,  and 
the  vinegar  eels  die  from  the  want  of  it.  By  opening  the 
draught-holes  and  pouring  in  alcoholic  liquid,  the  normal 
formation  of  vinegar  soon  recommences. 

The  killing  of  a  large  number  of  vinegar  eels  in  the  above 
manner  is,  however,  of  considerable  danger  to  the  regular 
working  of  the  factory,  and  the  respective  generators  must  be 
watched  with  special  care  in  order  to  meet  at  once  any  appear- 
ance of  putrefaction.  It  may  sometimes  succeed  to  keep  up 
the  work  undisturbed,  the  killed  vinegar  eels  being  gradually 
removed  from  the  generators  by  the  vinegar  running  off.  In 
such  critical  cases,  when  the  generator  may  at  any  moment 
commence  to  work  irregularly,  the  use  of  a  very  small  quan- 
tity of  salicylic  acid  as  an  addition  to  the  alcoholic  liquid 
would  be  advisable.  The  acid  by  checking  putrefaction  would 
prevent  the  immediate  decomposition  of  the  killed  vinegar 
eels  still  present  in  the  generators. 

Should,  however,  signs  of  putrefaction  appear,  energetic 
means  should  at  once  be  taken  to  arrest  its  progress,  it  being 
in  this  case  best  to  sulphur  the  generator.  This  is  effected  by 
closing  all  the  draught-holes  except  one,  and  introducing  into 
the  latter  the  nozzle  of  the  apparatus  whose  arrangement  is 
shown  in  Fig.  38. 

In  a  large  clay  vessel,  best  glazed  inside,  stands  upon  a  tripod 
a  shallow  dish.  The  cover  of  the  vessel  luted  air-tight  with  clay 
is  provided  with  three  openings.  The  opening  in  the  center  is 
closed  by  a  well-fitting  clay  stopper,  while  glass  tubes  bent  at 
a  right  angle  and  with  a  clear  diameter  of  about  J  inch  are 


DISTURBING    INFLUENCES    IN    MANUFACTURE. 


139 


cemented  in  the  openings  at  the  side.  The  tube  reaching 
nearly  down  to  the  plate  is  connected  by  means  of  a  rubber 
hose  with  a  double-acting  bellows,  while  the  second  tube  lead- 
ing directly  from  the  cover  is  connected  with  a  second  clay 
vessel.  From  the  cover  of  this  vessel  a  pipe  leads  to,  and  is 
fitted  into,  the  open  draught-hole  of  the  generator. 

For  use  the  apparatus  is  put  together,  as  shown  in  the  illus- 
tration, and  small  pieces  of  sulphur  are  thrown  through  the 
central  aperture  upon  the  dish.  The  sulphur  is  ignited  by 
throwing  in  a  lighted  sulphur  match,  and  after  closing  the 
aperture  the  bellows  is  put  in  operation.  The  product  of  the 

FIG.  38. 


combustion  of  the  sulphur  passes  through  the  tube  into  the 
generator,  and  in  ascending  dissolves  the  fluid  adhering  to  the 
shavings  to  sulphurous  acid.  The  addition  of  sulphur  and  the 
blowing-in  of  air  are  continued  until  the  odor  of  burning  sul- 
phur is  clearly  perceptible  in  the  upper  portion  of  the  genera- 
tor. The  second  vessel  which  contains  some  water  serves  for 
the  condensation  of  the  portion  of  the  sulphur  which  is  not 
consumed,  but  only  volatilized. 

The  sulphurous  acid  kills  every  living  organism  in  the  gen- 
erator, and  consequently  all  the  germs  of  the  vinegar  ferment 
are  also  destroyed. 

After  allowing  the  sulphured  generator  to  stand  a  few  hours, 


140  MANUFACTURE    OF    VINEGAR. 

fresh  air  alone  is  forced  through  it  by  means  of  the  bellows. 
The  air-holes  are  then  opened  and  the  generator  allowed  to- 
stand  a  few  days  for  the  sulphurous  acid  to  be  converted  into 
sulphuric  acid  by  the  absorption  of  oxygen.  To  bring  this 
generator  again  into  operation,  it  is  best  to  introduce  at  first  a 
number  of  pourings  consisting  only  of  vinegar,  with  a  content 
of  acetic  acid  corresponding  to  that  of  the  original  acetification. 
In  consequence  of  the  absorption  of  sulphuric  acid  by  the 
shavings,  this  vinegar  becomes  of  no  value  as  a  commercial 
article,  but  it  can  be  used  for  the  preparation  of  alcoholic 
liquid. 

The  last  traces  of  unchanged  sulphurous  acid  having  in  this 
manner  been  removed  from  the  generator  and  the  greater 
portion  of  sulphuric  acid  adhering  to  the  shavings  washed  out, 
the  generator  is  again  acetified,  this  being  best  effected  by 
pouring  in  alcoholic  liquid  just  run  off  from  correctly  working 
generators. 

Disturbances  Due  to  Vinegar  Lice  (Vinegar  Mites). — Unless 
the  most  scrupulous  cleanliness  prevails,  so-called  vinegar  lice 
will  always  be  found  in  the  factory.  They  prefer  places  kept 
constantly  moist,  and  to  which  the  air  has  access,  for  instance, 
the  draught-holes  and  the  interior  of  generators  beneath  the 
false  bottom.  As  a  rule,  manufacturers  do  not  pay  much  at- 
tention to  their  presence,  as  they  apparently  exert  no  influ- 
ence upon  the  regular  working.  That  such,  however,  is  not 
the  case,  will  be  seen  from  the  following  occurrence :  Some 
years  ago,  the  proprietor  of  a  vinegar  factory  in  Italy  informed 
Dr.  Bersch,  of  Vienna,  that  millions  of  small  animals  had 
appeared  in  the  factory  and  penetrated  into  the  generators, 
the  shavings  to  a  certain  height  being  covered  with  living 
and  dead  animals,  and  by  reason  of  the  latter  putrefying, 
further  operations  had  become  impossible.  Every  drop  of 
vinegar  running  off  from  the  generators  contained  one  or  more 
of  the  mites.  A  small  bottle  half  full  of  vinegar  and  closed 
air-tight  by  a  cork  accompanied  the  communication.  Al- 
though the  bottle  had  been  sixty  hours  in  transit,  on  opening 


DISTURBING    INFLUENCES    IN    MANUFACTURE. 


141 


it  a  number  of  living  animals  were  found,  congregated  especi- 
ally in  the  fissures  of  the  cork.  On  examining  them  with  the 
microscope  two  forms  (male  and  female?)  could  be  clearly  dis- 


FJG. 


tinguished,  many  being  only  one-quarter  or  one-half  the  size 
of  others.     Figs.  39  and  40  show  the  two  characteristic  forms 

FIG.  40. 


of  these  animalcules.     As  far  as  it  was  possible  to  determine 
their  zoological  position,  they  belong  to  the  family  Sarcoptidw. 


142  MANUFACTURE    OF    VINEGAR. 

No  particulars  as  to  their  origin  seem  to  be  known,  the  manu- 
facturer simply  stating  that  they  had  come  from  the  soil. under 
the  supports  of  the  generators  and  gradually  rendered  the 
latter  ineffective.  The  generators  were  sulphured  in  the 
manner  above  described,  and  again  put  into  operation. 

To  prevent  the  vinegar  mites  from  collecting  in  large  masses, 
scrupulous  cleanliness  must  prevail  in  the  factory.  Especially 
should  the  draught-holes  be  from  time  to  time  examined,  and, 
if  mites  be  found,  thoroughly  cleansed  with  hot  water,  which 
kills  them.  The  mites  might  also  be  prevented  from^  pene- 
trating into  the  interior  of  the  generators  by  rings  of  a  sticky 
substance  (turpentine)  around  the  draught-holes. 

Vinegar- Flies. — Though,  as  far  as  known,  the  animals 
known  as  vinegar-flies  create  no  disturbance  in  the  regular 
working  of  the  factory,  they  deserve  mention  because  they 
appear  wherever  a  fluid  passes  into  acetic  fermentation.  In 
wine  cellars,  not  kept  thoroughly  clean,  these  insects  are  fre- 
quently found  on  the  bung-holes  of  the  wine-barrels,  and  in 
factories  in  which  the  manufacture  of  wine  vinegar  is  carried 
on  according  to  the  old  system,  they  often  occur  in  great 
swarms. 

The  vinegar-fly  (Drosophila  funebris,  Meig)  is  at  the  utmost 
0.11  inch  long  ;  it  is  especially  distinguished  by  large  red  eyes 
sitting  on  both  sides  of  the  head  and  meeting  in  front.  The 
thorax  and  legs  are  red  ;  the  abdomen,  which  is  provided  with 
six  rings,  is  black,  with  yellow  stripes.  The  wings  are  longer 
than  the  body.  The  larva  is  white,  has  twelve  rings,  on  the 
mouth  two  black  hook-like  structures,  and  on  the  back  part  of 
the  body  four  warts,  two  of  which  are  yellow.  In  eight  days 
the  larva  is  transformed  into  a  yellow  chrysalis. 

The  collection  of  these  flies  in  large  masses  can  be  readily 
prevented  by  keeping  the  factory  thoroughly  clean  and  being 
especially  careful  not  to  spill  any  fluid. 


SLOW    PROCESS    OF    MAKING    VINEGAR.  143 

CHAPTER  XIV. 

SLOW    PROCESS    OF    MAKING    VINEGAR. 

IN  the  manufacture  by  the  slow  process,  barrels  thoroughly 
cleansed  with  boiling  water  and  previously  saturated  with  hot 
vinegar  are  used.  The  bung-holes  are  left  open  or  loosely 
covered.  Smaller  barrels  with  a  capacity  of  from  15  to  25 
gallons  are  preferred,  and  earthenware  pots  holding  only  3  to 

5  gallons  are  also  used,  it  being  claimed  that  they  are  espe- 
cially suitable  for  the  preparation  of  very  strong  vinegar.    The 
barrels  are  arranged  in  tiers  upon  wooden  supports  in  such  a 
manner  that  their  contents  can  be  readily  withdrawn  by  means 
of  a  faucet  or  a  siphon.    The  heating  apparatus  may  be  either 
stoves,  a  hot-air  furnace,  or  an  arrangement  similar  to  that 
employed   in    heating   hot-houses.      Due   attention   must   be 
given  to  the  methods  of  maintaining  an  equable  temperature. 

For  the  induction  of  the  formation  of  vinegar,  finished 
vinegar  should  be  added  to  the  dilute  alcohol.  By  adding  a 
few  slices  of  bread,  or  beer  wort,  or  a  decoction  of  resins,  the 
formation  of  vinegar  can  in  many  cases  be  accelerated,  the 
substances  named  offering  nutriment  to  the  vinegar  ferment. 

The  mixture  of  weak  alcohol  and  vinegar  is  called  wash.  It 
is  prepared  from  whiskey  or  alcohol,  to  which  sufficient  water 
is  added  that  the  mixture  shows  a  content  of  about  6  per  cent, 
of  alcohol.  To  this  weak  spirit  one-quarter  or  one-half  of  its 
volume  of  vinegar  is  added.  Suppose  vinegar  containing  4J 
per  cent,  of  acetic  anhydride  is  to  be  made.  Theoretically,  the 
wash  should  contain  a  little  over  5  per  cent,  absolute  alcohol, 
but  on  account  of  the  loss  by  evaporation  of  alcohol,  a  wash  of 

6  per  cent,  must  be  used.     If  in  making  this  wash  80  per  cent, 
alcohol  is  employed,  then  the  latter  would  have  to  be  diluted 
so  that  every  gallon  of  it  becomes  13f\  gallons.     In  other 
words,  to  100  gallons  of  80  per  cent,  alcohol  1,250  gallons  of 
water  are  added,  which  makes  1,330  gallons  of  mixture,  and 


144  MANUFACTURE  OF  VINEGAR. 

this,  after  the  addition  of  300  gallons  of  vinegar,  becomes  1,630 
gallons  of  wash.  A  portion  of  the  water  must  be  taken  suffi- 
ciently hot  to  give  a  temperature  of  90°  to  100°  F.  to  the 
wash.  The  resulting  wash  is  placed  in  the  fermenting  barrels 
to  fill  each  one  two-thirds  full,  and  the  temperature  of  the 
apartment,  observed  by  thermometers  placed  in  different  parts 
of  it,  must  be  kept  at  between  75°  and  100°  F.  At  the  mini- 
mum temperature  less  fuel  is  required,  but  the  time  needed 
for  acetification  is  extended,  and  consequently  more  barrels 
and  a  larger  apartment  are  needed  to  make  the  same  amount 
of  vinegar.  With  the  maximum  temperature  the  reverse  is 
the  case. 

Several  days  after  the  addition  of  the  wash  acetification  be- 
gins, and  is  indicated  by  a  temperature  in  the  barrels  slightly 
above  that  of  the  apartment.  A  piece  of  stone  or  slate,  which 
is  usually  laid  over  the  bung-hole  of  each  barrel  to  prevent  too 
great  evaporation  and  consequent  cooling,  is  bedewed  with 
moisture,  and  a  pungent  acid  odor  is  perceived  in  the  room. 
As  long  as  these  indications  continue,  everything  is  going  on 
well,  but  every  barrel  must  be  examined  by  itself  to  at  once 
restore  activity  in  any  "  lazy  "  one,  lest  putrefaction  or  mpuldi- 
ness  take  place  and  spread  to  the  neighboring  barrels.  When 
this  misfortune  occurs,  the  bad  barrels  are  at  once  removed 
from  the  apartment,  their  contents  thrown  away,  and  the 
barrels  scoured  well  with  brushes  and  water,  and  placed  in  the 
sun.  After  they  are  dry  they  may  be  saturated  with  hot  vine- 
gar and  brought  into  action  again.  If  only  "  lazy,"  they  are 
excited  by  withdrawing  a  portion  of  their  contents,  which  is 
warmed  in  glass  bottles,  and  with  the  addition  of  a  little  alco- 
hol and  vinegar  is  restored  to  the  casks. 

Too  cool  a  location  or  a  constant  draught  of  air  will  some- 
times put  a  cask  out  of  action.  This  is  remedied  by  re- 
moval, after  acetification  is  restored,  to  a  warmer  location,  or 
by  covering  with  a  non-conductor,  such  as  heavy  paper  pasted 
over  it. 

After  a  lapse  of  time  dependent  on  the  temperature  which 


SLOW    PROCESS    OF    MAKING    VINEGAR.  145 

is  kept  somewhat  higher  towards  the  end  of  the  operation, 
acetification  is  complete.  Otto  gives  the  time  generally  re- 
quired as  follows : 

With  a  temperature  of  Weeks  required. 
95°  to  100°  F.  2  to   4. 

86°  to    95°  F.  4  to   8. 

72°  to    86°  F.  8  to  16. 

The  close  of  acetification  is  indicated  by  the  diminution  of 
the  strong  vinegar  smell  in  the  room,  by  the  absence  of  vapor 
condensing  upon  the  slate  covers  of  the  bung-holes,  and  by 
the  temperature  of  the  inside  of  the  barrels  becoming  equal  to 
that  of  the  room. 

As  soon  as  acetification  in  any  one  barrel  is  perfected,  the 
vinegar  must  at  once  be  withdrawn,  barreled  and  removed  to 
a  cooler  place  than  the  vinegar  room,  in  which  its  tendency 
to  spoil  in  the  heated  atmosphere  is  very  great.  The  slimy  de- 
posit called  "  mother  of  vinegar  "  is  removed,  and  the  vinegar 
with  which  it  is  imbued,  employed  in  part  for  the  next  aceti- 
fication. If  the  sediment  from  each  barrel  be  placed  in  a  cask, 
the  clear  vinegar  may  be  drawn  off  after  the  deposition  of  the 
mother  of  vinegar.  It  is  well  before  barreling  the  vinegar,  to 
allow  it  to  stand  for  a  short  time  in  a  cool  room  in  a  vessel 
filled  with  beech  shavings,  which  clarify  it.  When  stored,  a 
pint  of  spirits  should  be  added  to  each  barrel. 

As  previously  mentioned,  the  slow  process  above  described 
may  be  modified  in  various  ways.  Thus,  instead  of  bringing 
the  fermentation  to  completion  in  all  of  the  barrels  at  about  the 
same  time,  they  may  be  divided  into  three  or  four  groups,  so 
that  J  or  J  of  the  whole  quantity  of  vinegar  may  be  with- 
drawn, and  stored  at  intervals  of  J  to  J  the  time  required  for 
the  acetification  of  the  whole  quantity.  This  modification  has 
the  advantage  of  a  greater  distribution  of  the  work  ;  necessity 
of  a  smaller  quantity  of  vinegar  stored  for  sale,  and  the  pres- 
ence of  barrels  in  full  action,  emitting  strongly  acetic  vapors, 
which  is  of  advantage  in  keeping  up  fermentation  in  barrels 
10 


146  MANUFACTURE  OF  VINEGAR. 

just  going  into  operation.  The  disadvantages  consist  in  greater 
need  for  entering  and  leaving  the  vinegar  room,  involving 
loss  of  its  heat,  and  requiring  in  consequence  greater  attention 
to  its  fires.  In  addition  to  this  the  heat  cannot  be  increased 
towards  the  close  of  acetifi cation,  which  is  useful  in  shortening 
the  time  for  manufacture. 

Another  modication  consists  in  always  keeping  a  large 
quantity  of  vinegar  in  the  fermenting  barrels,  and  at  short 
intervals  withdrawing  small  quantities  of  vinegar  which  are 
replaced  by  fresh  wash.  This  saves  time,  as  acetification  is 
more  rapid  in  the  presence  of  large  bodies  of  vinegar.  It 
involves  loss  of  heat  by  a  need  for  too  frequently  entering  the 
vinegar  room.  It  involves  also  a  loss  of'  interest  upon  the 
value  of  the  large  quantity  of  vinegar  kept  in  the  fermenting 
barrels.  The  intervals  at  which  vinegar  may  be  withdrawn 
are  closer  in  proportion  to  the  heat  of  the  apartment,  which 
bears  a  ratio  to  the  amount  of  fuel  consumed. 

By  this  method  only  -J  of  the  vinegar  is  removed  at  one  time 
from  each  barrel ;  in  other  words,  at  intervals  of  one  to  two 
weeks,  according  to  temperature,  one  gallon  of  vinegar  is  with- 
drawn from  every  5  gallons  in  the  fermenting  barrels,  and  in  its- 
stead  a  gallon  of  wash  is  added.  In  a  large  factory,  the  latter 
process  requires  a  large  number  of  barrels  of  vinegar  to  com- 
mence operations.  The  vinegar  must  be  either  purchased  or 
made  gradually  in  the  fermenting  barrels,  not  withdrawing  any 
until  the  barrels  are  sufficiently  full.  The  advantage  consists 
in  a  smaller  number  of  fermenting  barrels  being  required  than 
by  the  method  first  described.  Dr.  Otto  gives  the  following 
calculation  for  the  number  of  fermenting  barrels  required  for 
the  slow  process : 

Suppose  that  it  is  required  to  furnish  a  barrel  of  vinegar  per 
day,  excluding  Sundays,  which  would  equal  312  forty-gallon 
barrels  per  year,  the  fermenting  barrels  would  have  each  a  ca- 
pacity of  J  barrel,  and  since  they  are  not  filled  with  wash,  and 
on  account  of  unavoidable  loss,  four  such  barrels  may  be  allowed 
to  each  barrel  of  vinegar  made.  What  is  added  to  make  the 


SLOW    PROCESS    OF    MAKING    VINEGAR.  147 

wash  is,  of  course,  not  accounted  as  manufactured  vinegar,  as 
a  like  quantity  must  be  added  in  the  subsequent  wash.  From 
every  four  fermenting  barrels,  one  barrel  of  vinegar  may  be 
sold,  and  hence  6  barrels  of  vinegar  will  require  24  fermenting 
barrels.  If  the  workroom  be  so  heated  that  the  operation  is 
completed  in  four  weeks,  24  barrels  of  vinegar  will  have  to  be 
drawn  off,  to  do  which  96  fermenting  barrels  will  be  required. 
If,  however,  a  lower  temperature  be  maintained  in  the  work- 
room, say  to  complete  the  process  in  16  weeks,  4  times  96  = 
384  fermenting  barrels,  will  be  required.  In  the  latter  case 
the  expense  of  fuel  is  lessened,  but  that  of  the  fermenting 
barrels  is  increased.  Besides,  a  larger  apartment  will  be  neces- 
sary, which  will  involve  a  higher  rent  and  greater  expense  for 
fuel  in  heating  it.  If  the  process  be  modified,  as  described,  so 
that  a  large  body  of  vinegar  is  always  kept  in  the  fermenting 
barrels,  their  number  may,  as  before  stated,  be  proportionately 
decreased. 

This  calculation  affords  the  very  best  illustration  of  the 
superiority  of  the  modern  quick  process,  over  the  old  slow 
method.  To  make  one  barrel  per  day  by  the  quick  process,  a 
small  room  and  two  generators  are  the  only  requisites. 

Household  Manufacture  of  Vinegar. — The  following  method 
is  to  be  recommended  as  simple,  expedient,  and  furnishing  a 
constant  supply  of  vinegar  with  scarcely  any  trouble  and  at 
trifling  cost : 

Procure  two  barrels,  the  one  for  making,  the  other  for  stor- 
ing the  vinegar,  barrels  from  which  good  vinegar  has  just  been 
drawn  being  preferable.  The  storage  barrel  is  always  kept  in 
the  cellar,  and  the  generating  barrel  in  the  house  or  cellar,  ac- 
cording to  the  season.  At  the  top  of  one  of  the  heads  of  the 
storage  barrel  a  small  hole  is  bored  for  the  circulation  of  air. 
The  barrels  lie  on  their  side,  and  each  of  them  is  furnished 
with  a  wooden  faucet.  Their  capacity  is,  of  course,  regulated 
by  the  yearly  demand. 

Suppose  that  the  generator,  filled  to  the  level  of  the  venti- 
lating hole,  contains  10  gallons,  the  manufacture  will  then 


148  MANUFACTURE    OF    VINEGAR. 

be  carried  on  as  follows :  Seven  gallons  of  vinegar  of  a  good 
quality  are  placed  in  the  barrel,  and  three  gallons  of  warm 
alcoholic  liquid  are  added.  This  alcoholic  liquid  is  made  as 
follows:  If  common  50  per  cent,  whisky  be  employed,  have  a 
small  measure  of  3  pints  and  a  large  one  (a  bucket)  of  3 
gallons.  If  86  per  cent,  alcohol  is  used,  let  the  small  measure 
be  for  2  pints.  Put  a  small  measureful  of  spirits  in  the  large 
measure ;  fill  quickly  to  the  mark  with  boiling  water,  and 
pour  by  means  of  a  funnel  into  the  generator.  Every  two  or 
three  weeks,  three  gallons  of  vinegar  are  withdrawn  from  the 
generator  and  added  to  the  storage  barrel,  and  three  gallons  of 
alcoholic  liquid  are  placed  in  the  generating  barrel  as  before. 

Another  method  of  working  the  casks  consists  in  half  filling 
the  generator  with  vinegar,  and  adding  every  week  so  much 
of  the  alcoholic  liquid  that  it  fills  the  barrel  in  from  8  to  16 
weeks,  according  to  the  season.  Half  the  vinegar  is  then 
added  to  the  storage  cask,  and  the  process  then  recommenced 
iri  the  generator.  The  warmer  the  season  the  more  rapid 
may  be  the  manufacture. 

Preparation  of  Vinegar  with  the  Assistance  of  Platinum  Black. 
— In  considering  the  theory  of  the  formation  of  vinegar  it  was 
mentioned  that  platinum  in  a  finely  divided  state  possesses  the 
property  of  converting  alcohol  into  acetic  acid.  This  property 
of  platinum  has  been  utilized  for  the  purpose  of  manufacturing 
acetic  acid  on  a  large  scale.  The  apparatus  used  for  this  pur- 
pose consists  of  a  small  glass  house,  provided  in  the  interior 
with  a  number  of  compartments.  The  shelves  forming  these 
compartments  support  a  number  of  porcelain  capsules.  The 
alcohol  to  be  acetified  is  poured  into  these  capsules,  in  each  of 
which  is  placed  a  tripod,  also  of  porcelain,  supporting  a  watch- 
glass  containing  platinum  black  or  spongy  platinum.  In  the 
roof  and  at  the  bottom  of  the  apparatus  are  ventilators,  so  con- 
structed as  to  admit  of  regulating  the  access  of  air.  By  means 
of  a  small  steam-pipe  the  interior  of  the  house  is  heated  to  79° 
F.  By  this  means  the  alcohol  is  gently  evaporated,  and  com- 
ing in  contact  with  the  platinum  black  or  sponge  is  acetified. 


TREATMENT    OF    FRESHLY-PREPARED    VINEGAR.  149 

So  long  as  the  ventilation  is  maintained,  the  platinum  black 
retains  its  property  of  oxidizing  the  alcohol.  With  an  appa- 
ratus of  52  cubic  yards'  capacity  and  with  37  pounds  of  plati- 
num black,  150  quarts  of  alcohol  can  daily  be  converted  into 
pure  vinegar.  The  drawbacks  to  this  process  are  high  prices 
for  alcohol,  and  the  large  quantity  of  the  very  expensive 
platinum  required  for  working  on  a  manufacturing  scale. 


CHAPTER  XV. 

FURTHER    TREATMENT    OF    FRESHLY-PREPARED    VINEGAR. 

THE  vinegar  running  off  from  the  generators  is  "  finished  " 
in  so  far  that  it  contains  the  quantity  of  acetic  acid  obtainable 
from  the  content  of  alcohol  in  the  alcoholic  liquid,  but  it  be- 
comes a  commercial  article  only  by  long  storing  and  special 
treatment. 

The  odor  of  freshly  prepared  vinegar  is  by  no  means  agree- 
able. It  is  very  pungent  and  at  the  same  time  stupefying, 
the  latter  property  being  no  doubt  due  to  small  quantities  of 
aldehyde  contained  in  it,  which,  however,  volatilize  or  oxidize 
by  storing.  The  odor  depends  largely  on  the  materials  used 
in  the  manufacture,  that  of  vinegar  prepared  from  an  alcoholic 
liquid  composed  of  water  and  alcohol  alone  without  an  addi- 
tion of  beer  being  decidedly  the  least  agreeable.  By  long 
storing  such  vinegar  acquires  a  somewhat  finer  odor,  but  never 
especially  agreeable  properties. 

The  barrels  for  storing  fresh  vinegar  should  be  filled  up  to 
the  bung-holes  and  closed  air-tight,  since  when  air  is  present 
the  ferment  in  the  absence  of  alcohol  consumes  acetic  acid, 
thus  reducing  the  strength  of  the  vinegar  ;  and  moreover,  mold 
ferment  might  develop. 

The  temperature  of  the  vinegar  running  off  from  the  gener- 
ators being  quite  high,  its  volume  diminishes  on  cooling,  and 


150  MANUFACTURE  OF  VINEGAR. 

consequently  the  barrels  when  inspected  later  on  will  not  be 
quite  full.  When  the  vinegar  is  stored  in  barrels  not  made 
air-tight  by  a  suitable  coating  (lacquer,  paraffin,  etc.),  the  air 
penetrates  through  the  pores  of  the  wood  and  a  constant  re- 
ciprocal action  takes  place  between  it  and  the  vinegar.  The 
very  slow  oxidation  thus  produced  exerts  a  decidedly  favorable 
influence  upon  the  odor  of  the  vinegar,  the  processes  thereby 
taking  place  being  somewhat  similar  to  those  which  cause  the 
formation  of  the  bouquet  in  wine.  This  similarity  extends 
also  to  the  fact  that  the  vinegar  bouquet,  if  it  may  so  be  called, 
is  the  finer  the  slower  the  effect  of  the  oxygen,  and  this  can 
be  reached  by  storing  the  barrels  in  a  warehouse  having  a 
temperature  of  from  57°  to  GO0  F.,  or  in  a  cellar. 

It  has  been  sought  to  improve  the  odor  of  vinegar  by  various 
additions,  but  that  of  volatile  oils,  such  as  oils  of  caraway, 
fennel,  anise,  etc.,  which  has  been  frequently  proposed  for  the 
purpose,  cannot  be  recommended.  These  oils,  to  be  sure,  give 
a  specific,  agreeable  odor  to  the  vinegar,  but  an  expert  can  at 
once  detect  such  additions.  More  suitable  for  the  purpose  is 
the  use  of  a  very  small  quantity  (a  few  hundred-thousandths 
of  the  weight  of  the  vinegar)  of  potato  or  grain  fusel  oil,  these 
bodies  forming  with  the  corresponding  quantity  of  acetic  acid 
the  frequently  mentioned  odoriferous  compound  ethers.  An 
addition  of  J  per  cent,  of  very  strong  alcohol  to  the  vinegar 
has  also  a  very  favorable  effect  upon  the  odor  of  the  latter, 
acetic  ether  being  formed  in  storing.  In  place  of  alcohol, 
acetic  ether  or  amyl  acetate  (pear  essence)  can  be  directly 
added,  but  only  in  very  small  quantities  and  best  in  alcoholic 
solutions  of  a  determined  content,  for  instance,  50  grammes  of 
pear  essence  to  1  liter  of  95  per  cent,  alcohol.  Of  this  solution 
0.1  liter  (=  100  cubic  centimeters)  contains  5  grammes  of  pear 
essence,  and  if  added  to  100  liters  of  vinegar,  which  in  round 
numbers  weigh  100  kilogrammes,  the  latter  will  contain  Tooicro 
of  pear  essence.  By  proceeding  in  this  manner  the  correct 
quantity  required  can  be  readily  determined.  Immediately 
after  the  addition  of  one  of  the  above-mentioned  substances 


TREATMENT    OF    FRESHLY-PREPARED    VINEGAR. 


151 


its  odor  is  disagreeably  prominent,  but  becomes  pleasant  by 
storing. 

After  lying  for  several  weeks  a  muddy  sediment  forms  on  the 
deepest  place  of  the  barrel.  The  vinegar  can  be  carefully 
drawn  off  from  this  sediment  by  means  of  a  rubber  hose ;  or  a 
special  apparatus,  similar  to  that  shown  in  Fig.  41,  is  used  for 
the  purpose.  It  consists  of  the  glass  tube  a,  which  is  inserted 
in  the  tap-hole  of  the  barrel  and  reaches  to  the  bottom,  where 
it  is  slightly  bent  'upwards.  In  front  of  the  bung-hole  this 
tube  is  provided  with  a  bulb  in  which  is  fitted  by  means  of  a 
cork  a  tube,  b,  bent  at  a  right  angle.  While  the  vinegar  is 
stored,  this  tube  stands  upright  as  indicated  by  the  dotted 

FIG.  41. 


lines,  and  is  secured  to  a  rubber  hose  reaching,  up  to  the 
bung-hole.  By  turning  the  tube  downward,  the  fluid  runs 
out  through  the  tube  a,  until  its  level  has  sunk  to  the  dotted 
line. 

Sometimes  the  vinegar  is  not  rendered  perfectly  clear  by 
storing,  and  filtering  has  to  be  resorted  to.  Before  referring 
to  this  operation  a  few  words  will  be  said  in  regard  to  the 
storing  of  vinegar. 

The  vinegar  brought  into  the  storage  barrels  contains  the 
following  constituents:  Water,  acetic  acid,  alcohol  (very 
little),  aldehyde  (very  little),  acetic  ether,  vinegar  ferment 
(living  and  dead),  extractive  substances  (depending  on  the 


152  MANUFACTURE    OF    VINEGAR. 

nature  of  the  alcoholic  liquid  used).  Moreover,  there  are  fre- 
quently found  alcoholic  ferment  (from  the  beer),  and  vinegar 
eels  and  vinegar  mites,  if  these  animals  exist  in  the  factory. 

By  filling  the  storage  barrels  to  the  bung-holes  and  closing 
them  air-tight,  the  vinegar  eels  and  vinegar  mites  die  in  a  short 
time  for  want  of  air,  and  fall  to  the  bottom.  The  living  vine- 
gar ferment  present  in  the  fluid  must  assume  the  form  in  which 
it  can  for  some  time  exist  without  free  oxygen,  i.  e.,  of  mother 
of  vinegar.  When  in  consequence  of  the  shrinkage  in  the 
volume  of  the  vinegar  by  cooling,  the  air  penetrates  through 
the  pores  of  the  wood,  it  is  first  utilized  for  the  conversion  of 
the  small  quantity  of  aldehyde  into  acetic  acid,  and  later  on 
enables  the  vinegar  ferment  to  continue  to  exist  upon  the  sur- 
face and  to  slowly  convert  the  small  quantity  of  alcohol  still 
present  into  acetic  acid. 

If  the  barrels  are  not  closed  absolutely  air-tight,  the  vinegar 
ferment  will  develop  quite  vigorously  upon  the  surface,  and 
when  all  the  alcohol  is  consumed  attack  the  acetic  acid,  so  that 
when  the  vinegar  is  tested  a  decrease  in  the  content  of  acetic 
acid  is  plainly  perceptible.  If  the  finished  vinegar  still  con- 
tains considerable  quantities  of  albuminous  substances  in  solu- 
tion (vinegar  from  grain,  malt,  or  fruit),  or  if  it  contains 
tartaric  and  malic  acids  and  at  the  same  time  only  a  small  per- 
centage of  acetic  acid,  as  most  fruit  vinegars  do  (seldom  more 
than  5  per  cent.),  Ihe  mold  ferment  readily  settles  upon  the 
vinegar  and  finally  dislodges  the  vinegar  ferment  from  the 
surface.  The  acetic  acid  is,  however,  very  rapidly  destroyed 
by  the  mold  ferment,  and  through  a  luxuriant  growth  of  the 
latter,  which  floats  upon  the  surface  as  a  white  membranous 
coating,  the  vinegar  may  in  a  few  weeks  lose  one  or  more  per 
cent,  of  it.  This  happens  so  frequently,  for  instance  with  fruit- 
vinegar,  that  the  opinion  that  such  vinegar  cannot  be  made  to 
keep,  is  quite  general. 

Vinegar  which,  besides  a  considerable  quantity  of  extractive 
substances,  contains  the  salts  of  certain  organic  acids  (malic 
and  tartaric  acids),  for  instance,  vinegar  prepared  from  apples 


TREATMENT    OF    FRESHLY-PREPARED    VINEGAR.  153 

or  wine,  must  be  frequently  examined,  as  it  readily  spoils,  and 
may  suffer  even  if  kept  in  barrels  constantly  filled  up  to  the 
bung.  In  fluids  containing  the  salts  of  the  above-mentioned 
organic  acids  a  ferment  may  frequently  develop,  even  when  the 
air  is  excluded,  which  first  decomposes  the.  tartaric  and  malic 
acids,  and  though  these  acids  are  present  only  in  a  compara- 
tively small  quantity,  they  influence,  to  a  considerable  extent, 
the  flavor  of  the  vinegar  on  account  of  their  agreeable  acid 
taste.  In  vinegar  in  which  this  ferment  has  long  existed  a 
diminution  of  acidity  can  be  readily  detected  by  the  taste,  and 
by  the  direct  determination  of  the  acid  a  decrease  in  its  con- 
tent can  be  shown  which,  if  calculated  as  acetic  acid,  may  in 
some  cases  amount  to  one  per  cent.  Besides  the  loss  of  its 
former  agreeable  taste,  vinegar  thus  changed  acquires  a  harsh 
tang,  due  no  doubt  to  the  formation  of  certain  products  not 
yet  known  formed  by  the  ferment  effecting  the  destruction  of 
the  tartaric  and  rnalic  acids.  Moreover,  wine  or  fruit-vinegars 
in  which  this  ferment  has  for  a  considerable  time  flourished, 
lose  their  characteristic  agreeable  bouquet  which  may  be  con- 
sidered the  greatest  damage. 

In  the  presence  of  a  large  number  of  vinegar  eels  their  bodies 
may  decay  and  impart  to  the  vinegar  a  very  disagreeable 
putrid  odor,  even  if  stored  in  barrels  closed  air-tight. 

The  advisability  of  filtering  the  vinegar  before  bringing  it 
into  the  storage  barrels  will  be  readily  understood  from  the 
above  statement.  By  filtration  it  is,  however,  only  possible  to 
remove  the  vinegar  eels  and  vinegar  mites  swimming  in  the 
fluid  and  larger  flakes  of  mother  of  vinegar.  The  ferments 
and  bacteria  inducing  putrefaction  cannot  be  thus  removed, 
so  that  even  filtered  vinegar  is  liable  to  spoil  when  stored. 

Heating  the  Vinegar. — In  order  to  destroy  all  organisms 
which  might  cause  the  spoiling  of  the  vinegar,  it  is  recom- 
mended to  heat  the  latter  to  about  140°  F.  before  running  it 
into  the  storage  barrels.  A  few  moments  exposure  at  this 
temperature  being  sufficient  for  the  purpose,  a  large  volume 
of  vinegar  can  in  a  short  time  be  heated  with  the  use  of  a  suit- 
able apparatus,  such  as  is  shown  in  Fig.  42. 


154 


MANUFACTURE    OF    VINEGAR. 


In  the  head  of  the  barrel  b  is  secured  a  pipe  of  pure  tin  with 
very  thin  walls  and  a  clear  diameter  of  about  j-  inch.  It  is 
-coiled  in  a  boiler  filled  with  water,  which  it  enters  at  e/and 
leaves  at  h.  It  then  passes  into  the  barrel  b,  in  which  it  is  also 
coiled,  and  ends  outside  the  barrel  at  g.  At  i  it  expands  to  a 
bulb  in  which  a  thermometer,  t,  is  placed.  A  vat,  a,  placed  at 
a  certain  height  above  the  barrel  is  provided  with  a  wooden 
stop-cock,  c,  to  which  is  secured  a  rubber  hose,  d,  which  enters 
the  barrel  b  above  the  bottom.  The  pipe  k,  which  is  secured 
on  top  of  the  barrel  b,  is  open  on  both  ends  and  of  sufficient 
length  to  project  above  the  vat  a. 

FIG.  42. 


The  boiler  is  filled  with  water  and  placed  in  an  ordinary 
hearth.  The  vat  a  is  filled  with  the  vinegar  to  be  heated  and 
kept  constantly  supplied.  The  water  being  heated  to  boiling, 
the  stop-cock  c  is  opened.  The  vinegar  now  runs  through  d 
into  the  barrel  b,  and,  after  filling  it,  flows  at  e  into  the  tin 
coil  and  in  passing  through  it  in  the  direction  of  the  arrows 
is  heated.  The  thermometer  t  dipping  into  the  hot  vinegar 
indicates  the  temperature,  and  the  inflow  of  vinegar  is  accord- 
ingly regulated  by  opening  or  closing  the  cock  c.  As  shown 
in  the  illustration,  the  hot  vinegar  runs  through  the  coil  sur- 


TREATMENT    OF    FRESHLY-PREPARED    VINEGAR.  155 

rounded  by  cold  vinegar  into  the  barrel  b,  whereby  it  is  cooled 
off  and  the  vinegar  in  the  barrel  preparatorily  heated.  The 
pipe  k,  open  on  both  ends,  allows  the  escape  of  the  gases  de- 
veloped. 

In  consequence  of  the  albuminous  substances  becoming  in- 
soluble by  heating,  the  vinegar  running  off  at  g  is,  as  a  rule, 
more  turbid  than  before.  It  is  brought  into  the  storage  bar- 
rels, which  need,  however,  not  be  closed  air-tight,  the  subse- 
quent processes  taking  place  in  the  vinegar  being  of  a  purely 
chemical  nature  and  not  caused  by  organisms.  The  latter 
have  been  killed  by  heating,  and,  together  with  all  other  for- 
eign bodies  suspended  in  the  vinegar,  gradually  fall  to  the 
bottom  of  the  barrel.  If  the  vinegar  after  heating  is  allowed 
to  lie  for  a  sufficiently  long  time,  it  clarifies  completely  and 
€an  be  drawn  off  perfectly  bright  from  the  sediment. 

Filtration  of  Vinegar. — The  bodies  suspended  in  the  vinegar 
and  causing  its  turbidity  being  very  small,  it  takes  some  time 
before  they  settle  on  the  bottom  and  the  fluid  becomes  entirely 
<?lear.  To  accelerate  clarification  the  vinegar  is  filtered. 

Fig.  43  shows  a  filter  suitable  for  the  purpose.  It  consists 
of  a  small,  strong  wooden  vat  provided  with  two  perforated 
false-bottoms,  s  and  b.  Upon  the  lower  false  bottom  is  spread 
a  linen  cloth  and  upon  it  fine  sand,  which  is  not  attacked  by 
acetic  acid,  or  small  pieces  of  charcoal.  Upon  the  smoothed 
surface  of  the  sand  is  spread  a  layer  of  paper  pulp  f  to  1  inch 
deep  which  is  covered  with  a  linen  cloth  and  then  placed  upon 
the  false  bottom  b,  the  latter  being  forced  down  by  means  of 
the  screw  k  and  the  pieces  of  wood  r.  The  vinegar  to  be  fil- 
tered is  in  the  vat  a  which  is  connected  with  the  filtering  vat 
by  the  stop-cock  h  and  the  rubber  hose  s,  8  to  10  feet  long. 
By  opening  the  stop-cock  h  the  filter  stands  under  the  pres- 
sure of  a  column  of  fluid  8  to  10  feet  high  and  the  filtered 
vinegar  runs  off  through  an  aperture  in  the  side  of  the  filter- 
ing vat.  By  filling  the  filter  below  the  paper  pulp  with  fine 
sand,  the  latter  retains  the  greater  portion  of  the  solid  bodies 
suspended  in  the  vinegar,  and  it  will  be  a  considerable  time 


156 


MANUFACTURE    OF    VINEGAR. 


before  the  pores  of  the  paper  pulp  become  choked  up  to  such 
an  extent  as  to  require  its  renewal. 

Sharp,  fine-grained  sand  should  be  used  for  filtering.  It 
should  be  free  from  iron  and  sulphur  and  previous  to  use 
freed  as  much  as  possible  from  lime  and  earthy  constituents 
by  washing  in  pure  water  to  which  some  hydrochloric  or  tar- 
taric  acid  may  be  added.  Fine  white  quartz  sand  is  very 
suitable  for  the  purpose.  White  sea-sand  is  also  highly 
recommended  for  filtering  vinegar,  it  being  claimed  that  after 

FIG.  43. 


its  use  for  several  months  not  a  single  vinegar-eel  was  found 
in  the  filtered  product.  When  after  long  use  the  sand  be- 
comes so  closely  packed  that  the  vinegar  does  not  run  off  with 
the  rapidity  desired,  the  layer  of  slime  that  has  accumulated 
upon  the  sand  is  carefully  removed  and  the  sand  thoroughly 
washed  and  dried,  when  it  is  again  ready  for  use. 

An  arrangement  suitable  for  filtering  larger  quantities  of 
fluid  under  an  increased  pressure  is  shown  in  Fig.  44. 

It  consists  of  a  strong  linen  bag,  8,  about  16  inches  in  diam- 


TREATMENT    OF    FRESHLY-PREPARED    VINEGAR. 


157 


FIG.  44. 


eter,  and  a  jute  or  hemp  hose,  R,  open  at  both  ends  and  about 
6  inches  in  diameter.  The  bag  is  tied  by  means  of  pack-thread 
to  a  cylindrical  piece  of  wood  which  is  secured  to  a  suitable 
support.  The  bag  is  then  connected  by  means  of  the  rubber 
hose  K  with  the  reservoir  B,  which  contains  the  vinegar  to  be 
filtered,  and  is  placed  about  10  to  13  feet  above  the  support 
carrying  the  bag.  The  bag  is  folded  so  that  it  can  be  inserted 
in  the  hose  R,  the  latter  being  also  secured  to  the  cylindrical 
piece  of  wrood. 

By  gradually  opening  the  stop-cock  on  the  reservoir  the  bag 
is  filled  with  vinegar,  but  being 
enveloped  by  the  hose  R  cannot 
entirely  expand  but  only  so  far 
as  permitted  by  the  diameter  of 
R,  so  that  though  its  entire 
surface  acts  as  a  filter  a  large 
number  of  folds  are  formed,  and 
it  is  thus  protected  from  burst- 
ing, even  under  the  pressure  of 
a  column  of  fluid  of  consider- 
able height.  The  fluid  filter- 
ing through  the  bag  runs  down 
on  the  hose  and  collects  in  a 
vessel  placed  under  it. 

At  first  this  filter  generally 
does  not  act  entirely  satisfac- 
torily, the  fluid  running  off  tur- 
bid ;  and  this  continues  until 
the  pores  of  the  filter  have  be- 
come sufficiently  contracted  to 
retain  the  small  bodies  sus- 
pended in  the  fluid.  This  can, 
however,  be  remedied  by  stir- 
ring some  charcoal  powder  into 
the  first  portion  of  vinegar  to 
be  filtered.  The  charcoal  powder  adheres  to  the  sides  of  the 


158  MANUFACTURE    OF    VINEGAR. 

bag  and  contracts  the  pores  of  the  tissue  so  that  the  fluid  runs 
off  entirely  clear. 

By  subjecting  the  freshly-prepared  vinegar  to  heating  and 
filtering,  a  commercial  article  is  obtained  which  is  perfectly 
clear  and  does  not  spoil  by  keeping.  By  storing  it,  however, 
for  some  time  in  barrels  it  gains  considerable  in  fineness  of 
odor  and  taste.  Wine-vinegar,  cider-vinegar  and  fruit-vinegars 
in  general  should  positively  be  stored  for  some  time,  the 
odoriferous  bodies  which  make  these  varieties  so  valuable 
developing  only  by  that  means. 

Sulphuring  of  Vinegar. — Sulphuring  has  long  been  employed 
as  the  most  convenient  method  for  the  preservation  of  wine, 
and,  if  correctly  applied,  can  also  be  used  for  that  of  vinegar. 
But  as  sulphurous  acid  readily  dissolves  in  vinegar,  the  latter 
must  not  be  brought  in  direct  contact  with  the  gases  arising 
from  the  burning  sulphur. 

The  sulphuring  of  vinegar  is  best  executed  as  follows :  The 
barrel  intended  for  the  reception  of  the  vinegar  is  thoroughly 
rinsed  and  immediately  placed  in  the  storeroom.  Then  place 
a  sulphur  match  consisting  of  a  strip  of  linen  about  6  inches 
long  and  f  to  1  inch  broad  dipped  in  melted  sulphur  into  a 
perforated  sheet-iron  cylinder  about  8  inches  long  and  1  inch 
in  diameter,  secure  this  cylinder  to  a  wire,  and  after  igniting 
the  sulphur  match,  lower  it  from  the  bung-hole  to  the  center  of 
the  barrel.  The  sulphurous  acid  formed  by  the  combustion 
of  the  sulphur  is  at  once  dissolved  by  the  water  adhering  to 
the  interior  of  the  barrel.  A  sulphur  match  of  the  above  size 
suffices  for  a  barrel  of  100  to  125  gallons. 

If  the  sulphured  barrel  be  now  immediately  filled  with  vin- 
egar, the  sulphurous  acid  becomes  distributed  throughout  the 
fluid  and  kills  the  vinegar  ferment  as  well  as  all  other  fer- 
ments present,  so  that  the  vinegar  cannot  undergo  any  further 
change  except  it  come  again  in  contact  with  living  ferments. 

The  sulphurous  acid  dissolved  in  the  vinegar  is  after  some 
time  converted  into  sulphuric  acid  and  its  presence  can  be 
readily  detected.  It  may,  however,  be  remarked  that  the 


TREATMENT    OF    FRESHLY-PREPARED    VINEGAR. 

quantity  of  sulphuric  acid  which  reaches  the  vinegar  in  the 
above  manner  is  exceedingly  small,  and,  moreover,  is  partially 
fixed  to  the  mineral  bases  (lime  and  magnesia)  contained  in 
the  water  used  in  the  preparation  of  the  alcoholic  liquid. 
Hence  a  manufacturer  who  sulphurs  his  barrels  need  not  fear 
being  accused  of  having  adulterated  his  vinegar  by  the  direct 
addition  of  sulphuric  acid.  Sulphured  vinegar  must  be  stored 
at  least  several  weeks  before  it  is  salable,  the  odor  of  sulphur- 
ous acid  adhering  to  it  perceptibly,  and  disappearing  only  at 
the  rate  at  which  the  sulphurous  acid  is  converted  into  sul- 
phuric acid. 

Fining  Vinegar. — Similar  to  wine,  vinegar  can  be  obtained 
bright  by  "  fining  "  with  isinglass.  This  method  is  employed 
by  a  number  of  manufacturers  though  it  offers  no  advantages 
as  compared  with  filtration.  The  isinglass  to  be  used  is  pre- 
pared as  follows  :  Cut  with  a  pair  of  scissors  into  narrow  strips 
J  to  1  drachm  of  isinglass  for  every  20  gallons,  and  soak  it  in 
water  in  a  porcelain  dish  for  24  hours.  The  resulting  jelly- 
like  mass  is  pressed  through  a  linen  cloth.  A  solution  of  J  to 
|  drachms  of  tannin  for  every  20  gallons  is  then  added  to  the 
isinglass  and  the  mass  diluted  with  vinegar.  The  whole  is 
then  thrown  into  the  barrel  and  thoroughly  mixed  with  th& 
contents.  The  clarified  vinegar  is  finally  drawn  off  from  the 
sediment. 

Coloring  Vinegar. — Vinegar  prepared  from  alcohol  is  limpid 
as  water  or  only  slightly  colored.  Prior  to  the  general  intro- 
duction of  the  quick  process  consumers  "were  accustomed  to 
the  dark  yellow  product  prepared  from  wine  or  beer,  and  many 
are  still  prejudiced  against  slightly  colored  vinegar,  consider- 
ing it  weaker.  Unfounded  as  this  prejudice  is,  the  manufac- 
turer is  nevertheless  obliged  to  recognize  it,  and  to  suit  the 
public  taste,  must  color  his  vinegar  by  artificial  means.  Car- 
amel or  burnt  sugar  prepared  from  glucose  is  a  simple  and 
perfectly  harmless  coloring.  It  is  made  by  melting  the  glu- 
cose in  a  shallow  iron  vessel  over  a  fire,  stirring  constantly 
with  a  long-handled  spoon.  The  melted  mass  soon  turns 


160  MANUFACTURE    OF    VINEGAR. 

brown  and  rises  in  the  vessel.  The  conversion  into  caramel 
being  hastened  in  the  presence  of  alkalies,  the  addition  of  a 
small  quantity  of  pulverized  carbonate  of  ammonium — about 
If  to  2  per  cent,  of  the  weight  of  the  glucose  used — is  of  ser- 
vice at  this  stage.  The  mass  is  now  heated  with  constant  stir- 
ring until  it  becomes  black,  runs  from  the  spoon  in  viscous 
dark  brown  threads,  and  a  sample  dropped  upon  a  cold  sur- 
face congeals  to  a  black  mass  impervious  to  light  except  upon 
the  edges.  The  vessel  is  then  lifted  from  the  fire  and  the  con- 
tents poured  out  upon  metal  or  stone  plates.  The  taste  of  the 
congealed  mass  should  not  be  bitter,  or  at  least  only  slightly 
so.  On  exposure  to  the  air,  the  caramel  deliquesces  to  a  thick 
black  fluid,  and,  therefore,  it  should  immediately  after  its 
preparation,  be  converted  with  water  into  a  solution  of  the  con- 
sistency of  syrup,  such  concentrated  solution  keeping  better 
than  a  dilute  one  which  readily  molds.  Immediately  before 
use  the  solution  is  diluted  with  water,  and  enough  of  it  added 
to  the  vinegar  to  give  it  the  desired  coloration.  Some  manu- 
facturers use  molasses  or  dark  syrup  for  coloring  vinegar. 


CHAPTER  XVI. 

PREPARATION    OF    VINEGAR    FROM    VARIOUS    MATERIALS. 

SINCE  acetic  acid  is  formed  by  the  oxidation  of  alcohol,  vin- 
egar can,  of  course,  be  prepared  from  every  kind  of  fluid  con- 
taining alcohol,  such  as  beer,  wine,  cider,  as  well  as  from  the 
juice  of  sacchariferous  fruits  which  has  passed  into  alcoholic 
fermentation.  By  allowing  grain  to  germinate,  a  body  to 
which  the  term  diastase  is  applied  is  formed,  which  possesses 
the  property  of  converting  starch  into  fermentable  sugar  and 
dextrin  when  brought  in  contact  with  it  under  certain  con- 
ditions. Vinegar  can,  therefore,  be  prepared  from  starch — 
though  in  a  round-about  way — by  treating  the  latter  with 


PREPARATION  OF  VINEGAR  FROM  VARIOUS  MATERIALS.       161 

grain  containing  diastase  (malt),  whereby  it  is  converted  into 
maltose  and  dextrin.  The  fluid  (sweet  mash)  is  compounded 
with  yeast,  and  the  sugar — and  with  a  correct  execution  of  the 
process  the  dextrin  also — is  converted  into  alcohol  by  vinous 
fermentation.  The  resulting  alcoholic  liquid  can  then  be 
used  for  making  vinegar. 

Alcohol  or  spirits  of  wine  obtained  in  the  above-described 
manner  from  the  starch  contained  in  potatoes  or  grain  being  at 
present  the  chief  material  used  in  the  manufacture  of  vinegar, 
the  greater  portion  of  the  latter  brought  into  commerce  might 
actually  be  designated  potato  or  malt  vinegar  according  to  the 
elementary  material  used.  The  great  progress  made  in  modern 
times  in  the  preparation  of  malt,  brewing  of  beer,  and  in  the 
distilling  industry  has  been  accompanied  by  a  constantly  ex- 
tending division  of  labor.  While  formerly  every  brewer  and 
distiller  prepared  his  own  malt,  there  are  at  present  numerous 
establishments  exclusively  engaged  in  this  branch  of  the 
industry  which  sell  their  product  to  the  brewer  and  distiller. 
The  manufacturer  of  vinegar  who  did  not  use  materials  con- 
taining finished  alcohol  (beer  or  wine)  had  to  undertake  the 
laborious  work  of  making  the  malt  and  preparing  and  ferment- 
ing the  mash  in  order  to  obtain  an  alcoholic  liquid  which  he 
•could  finally  convert  into  vinegar.  With  the  present  im- 
provements in  the  preparation  of  malt  and  the  production  of 
alcohol,  the  vinegar  manufacturer  can  work  more  cheaply  by 
buying  the  alcohol,  and  the  manufacture  of  so-called  malt  or 
grain  vinegar  would  pay  only  where  heavy  taxes  prevent  the 
direct  use  of  alcohol. 

Formerly,  when,  in  consequence  of  defective  processes, 
many  a  brewing  or  batch  of  malt  spoiled,  it  was  used  for  mak- 
ing vinegar.  But,  as  a  rule,  the  vinegar  obtained  was  not 
of  a  fine  taste  and  remained  turbid,  and  besides,  the  operation 
was  frequently  interrupted  by  all  sorts  of  incidents,  which 
led  to  the  opinion  of  malt-vinegar  not  possessing  keeping 
properties. 

Beer-wort  judged  by  its  composition  does  not  seem  a  suit- 
11 


162  MANUFACTURE    OF    VINEGAR. 

able  material  for  making  vinegar.  Besides  a  certain  quan- 
tity of  fermentable  sugar  (maltose),  it  contains  a  considerable 
amount  of  dextrin  and  other  fermentable  bodies.  For  the 
purpose  of  making  vinegar  the  maltose  alone  can  be  consid- 
ered, it  being  the  only  fermentable  constituent  of  beer-wort. 
Hence,  vinegar  prepared  from  beer-wort  always  contains  a 
considerable  quantity  of  dextrin  and  extractive  substances, 
and,  consequently,  is  of  a  more  thickly  fluid  nature  than 
belongs  to  vinegar,  and  clarifies  with  difficulty.  Moreover, 
this  drawback  exerts  a  disturbing  influence  upon  the  behavior 
of  the  vinegar  when  stored,  it  being  frequently  changed  by 
further  processes  of  fermentation  into  a  slimy  fluid,  and  ac- 
quires an  insipid  taste  and  loses  a  large  portion  of  its  content 
of  acetic  acid. 

Alcoholic  mashes  containing  in  consequence  of  faulty  prepa- 
ration a  considerable  quantity  of  dextrin  show,  when  used  for 
making  vinegar,  a  behavior  similar  to  that  of  beerwort ;  the 
vinegar  obtained  clarifies  with  difficulty  and  does  not  keep 
well.  Fermented  whiskey-mashes  properly  prepared  contain, 
however,  only  very  small  quantities  of  dextrin  and  extractive 
substances,  and,  when  freed  by  filtration  from  admixed  husks, 
can  be  used  as  a  material  for  the  manufacture  of  vinegar  and 
yield  an  entirely  normal  product. 

According  to  experience,  the  process  of  the  formation  of 
vinegar  proceeds  in  the  most  uniform  manner  by  preparing 
the  alcoholic  liquid  from  dilute  alcohol,  and,  consequently,  in 
a  vinegar  factory  connected  with  a  distillery  it  would  be  best 
to  dilute  ti on-rectified  spirits  of  wine  with  the  required  quantity 
of  water  and  add  from  10  to  20  per  cent,  of  the  weight  of  the 
alcoholic  liquid  of  fermented  mash.  The  latter  containing 
salts  and  nitrogenous  substances  suitable  for  the  nourishment 
of  the  vinegar  ferment  serves,  in  this  case,  as  a  substitute  for 
the  beer  generally  used  in  vinegar  factories  for  the  prepara- 
tion of  alcoholic  liquid. 

Manufacture  of  Malt  or  Grain  Vinegar. — Under  certain  local 
conditions  the  manufacture  of  vinegat  from  malt,  with  or  with- 


PREPARATION  OF  VINEGAR  FROM  VARIOUS  MATERIALS.       163 

out  an  addition  of  grain,  can  be  profitably  carried  on  in  con- 
nection with  that  of  compressed  yeast.  Such  factories  for 
evident  reasons  not  being  established  on  an  extensive  scale,  a 
description  of  the  preparation  of  vinegar  in  connection  with 
that  of  compressed  yeast  without  the  use  of  expensive  machin- 
ery will  be  given. 

The  preparation  of  the  fundamental  material,  malt,  requir- 
ing much  labor  and  knowledge,  it  will  be  best  for  the  manu- 
facturer to  buy  the  article  already  prepared.  Malt  kiln  dried 
at  as  low  a  temperature  as  possible  and  yielding  a  light-col- 
ored extract  when  treated  with  warm  water  should  be  chosen. 
Many  malt  houses  prepare  such  malt  especially  for  distilling 
purposes.  Malt  prepared  for  brewing  purposes  is  after  the 
actual  kiln-drying  heated  to  a  temperature  frequently  exceed- 
ing 158°  F.  for  the  formation  of  certain  aromatic  combinations 
and  coloring  substances  which  are  to  impart  to  the  beer  a 
specific  taste  and  dark  color.  Independently  of  the  dark  color 
of  the  vinegar  prepared  from  such  malt,  it  contains  a  consider- 
able quantity  of  dextrin,  and  consequently  acquires  an  insipid 
by-taste,  clarifies  with  difficulty,  and  is  readily  subject  to  in- 
jurious alterations.  Malt,  as  is  well  known,  contains  diastase, 
which  in  mashing  with  water  effects  the  conversion  of  the 
starch  into  maltose  and  dextrin.  By  kiln-drying  at  a  very 
high  temperature  a  portion  of  the  diastase  is,  however,  rendered 
ineffective,  and  in  mashing  comparatively  little  maltose  but  a 
large  quantity  of  dextrin  is  formed.  Mashing,  in  this  case, 
would  have  to  be  continued  for  a  long  time  in  order  to  obtain 
a  larger  quantity  of  maltose. 

With  the  use  of  but  slightly  kiln-dried  malt,  in  which  the 
efficacy  of  the  diastase  has  not  been  injured  by  a  high  tem- 
perature, the  greatest  directly  obtainable  quantity  of  maltose 
and  the  smallest  amount  of  dextrin  are  procured.  The  pro- 
portion of  maltose  to  dextrin  is  in  this  case  as  4  : 1,  or  in  other 
words,  the  finished  mash  contains  about  80  per  cent,  of  mal- 
tose and  20  per  cent,  of  dextrin.  The  dextrin  cannot  be 
directly  converted  into  acetic  acid  by  the  vinegar  ferment  and 


164  MANUFACTURE  OF  VINEGAR. 

consequently  would  be  found  in  the  finished  product.  It  is, 
however,  possible  to  treat  the  finished  mash  in  such  a  manner 
that  the  total  quantity  of  dextrin  contained  in  it  can  be  con- 
verted into  maltose  and  the  latter  into  alcohol,  in  this  case 
the  theoretically  calculated  yield  of  vinegar  from  the  malt 
will  be  nearly  approached  in  practice,  arid  the  product  thus  ob- 
tained contain  only  a  small  quantity  of  extractive  substances 
of  the  malt  which  are  not  decomposed  by  alcoholic  or  acetic 
fermentation. 

Before  entering  upon  a  description  of  the  mashing  process, 
the  theoretical  part  in  mashing  will  be  briefly  discussed.  Malt 
contains  starch  and  diastase.  By  bringing  the  comminuted 
malt  in  contact  with  water  of  about  131°  to  133°  F.,  the  starch 
is  formed  into  paste  and  the  diastase  passes  into  solution.  By 
the  action  of  the  diastase  upon  the  starch,  the  latter  is  con- 
verted into  maltose  and  dextrin,  the  finished  mass  containing 
80.9  per  cent,  of  maltose  and  19.1  of  dextrin.  For  reasons 
given  later  on,  the  finished  mass  is  heated  for  a  short  time  to 
between  140°  and  141.8°  F.,  without,  however,  exceeding  this 
temperature,  and  then  cooled  off  to  the  degree  required  for  the 
induction  of  alcoholic  fermentation. 

Mash  prepared  in  this  manner  contains,  besides  the  stated 
quantities  of  maltose  and  dextrin,  effective  diastase,  i.  e.,  such 
as  possesses  the  power  of  liquefying  starch.  By  heating  to 
above  158°  F.  the  diastase  entirely  loses  this  property.  By 
compounding  a  mash  of  this  nature  with  yeast,  the  diastase 
with  the  simultaneous  action  of  the  yeast  is  able  to  convert  all 
the  dextrin  present  in  the  fluid  into  maltose,  and  consequently 
the  total  quantity  of  starch  originally  present  is  converted  into 
alcohol  by  this  peculiar  process,  to  which  the  term  after-effect 
of  the  diastase  has  been  applied. 

Unmalted  grain  being  cheaper  than  malt  and  the  latter 
containing  sufficient  diastase  to  convert  a  very  large  quantity 
of  starch  into  maltose  and  dextrin,  a  mixture  of  malt  and 
unmalted  grain  (equal  parts  of  both;  f  grain  and  J  malt,  etc.) 
can  be  used  instead  of  malt  alone.  The  latter  is,  however, 


PREPARATION  OF  VINEGAR  FROM  VARIOUS  MATERIALS.       1G5 

preferable  for  the  manufacture  of  vinegar,  it  yielding  a  product 
of  a  finer  taste  than  unmalted  grain.  The  mode  of  preparing 
the  mash  is  exactly  the  same  as  for  the  distillation  of  alcohol, 
and  as  the  necessary  information  can  be  obtained  from  any 
treatise  on  that  subject,  only  a  brief  sketch  of  the  operation 
will  here  be  given. 

The  malt  carefully  ground  is  mixed  with  cold  water  to  a 
thin  paste,  which  is  stirred  until  all  small  lumps  are  dissolved. 
This  mixing  of  the  ground  malt  with  water,  dougldng  in  as 
it  is  called,  can  be  effected  with  the  assistance  of  a  crutch  or 
rake,  but  best  in  a  vat  provided  with  a  mechanical  stirring 
apparatus. 

Doughing-in  being  finished,  water  of  140°  to  149°  F.  is  per- 
mitted to  run  in.  until  the  mash  shows  a  temperature  of  about 
131°  to  133°  F.  During  this  operation  the  mash  should  be 
constantly  stirred.  The  at  first  thickly  fluid  mass  will  soon 
be  observed  to  become  thinly  fluid  by  the  starch  paste  being 
converted  into  soluble  bodies.  Mashing  is  finished  in  2  to  2J 
hours,  and  will  be  the  more  complete  the  more  accurately  the 
temperature  is  maintained  at  131P  to  133°  F.  The  completion 
of  the  process  is  recognized  by  a  filtered  sample  cooled  to  the 
ordinary  temperature  remaining  colorless  after  the  addition  of 
iodine  solution. 

The  mash  having  reached  this  state,  sufficient  hot  water  is 
added  with  constant  stirring  to  raise  the  temperature  to  140° 
or  141.8°  F.  The  purpose  of  this  operation  is  to  render  all  fer- 
ments present  in  the  mash  ineffective.  Lactic  acid  ferment  and 
frequently  also  butyric  acid  ferment  always  adhere  to  the  malt, 
and,  if  allowed  to  develop  in  the  mash,  would  form  lactic  and 
butyric  acids  during  fermentation  which  would  be  injurious  to 
the  process  of  alcoholic  fermentation  as  well  as  to  the  proper- 
ties of  the  vinegar  to  be  manufactured.  The  mash  is  now  re- 
duced to  a  temperature  of  about  57°  or  59°  F.  by  bringing  it 
into  the  cooling-back  or  passing  it  through  a  system  of  refrig- 
erating pipes.  When  working  on  a  small  scale  the  mash  can 
be  suitably  cooled  by  allowing  cold  water  to  pass  through  a 
coil  placed  in  a  vat  containing  it. 


166  MANUFACTURE    OF    VINEGAR. 

The  strength  of  the  vinegar  to  be  manufactured  depends  on 
the  concentration  of  the  mash ;  mashes  showing  a  saccha- 
rometer  statement  of  20  per  cent,  contain  after  fermentation 
about  9J  per  cent,  of  alcohol  which  yields  vinegar  of  about  8 
per  cent.;  mashes  showing  18  per  cent,  yield  vinegar  of  about 
7  per  cent.,  so  that  1  per  cent,  of  acetic  acid  in  the  vinegar 
may  be  calculated  on  for  about  every  2J  degrees  indicated  by 
the  saccharometer. 

The  mash  is  now  set  with  yeast,  though  the  latter  may  be 
added  when  the  mash  still  shows  a  temperature  of  71. 5°  to 
75°  F.,  the  yeast  having  then  time  to  vigorously  propagate. 
Mashes  prepared  from  malt  alone  are  uncommonly  rich  in 
nourishing  substances  for  the  yeast,  the  latter  propagating 
abundantly  and  inducing  a  very  vigorous  process  of  fermenta- 
tion. This  can  be  profitably  utilized  by  combining  the  manu- 
facture of  vinegar  and  that  of  compressed  yeast,  a  valuable 
product  being  thus  obtained  without  any  extra  expense  and 
with  but  little  labor.  At  a  certain  stage  of  the  alcoholic  fer- 
mentation the  yeast  comes  to  the  surface  of  the  fluid  and  can 
be  lifted  off.  By  washing  the  yeast  once  or  twice  with  cold 
water  and  then  freeing  it  from  the  excess  of  water  by  pressing, 
compressed  yeast  is  obtained  which,  with  the  exception  of  the 
portion  to  be  used  for  setting  fresh  mashes,  can  be  sold. 

Up  to  the  completion  of  alcoholic  fermentation  the  treatment 
of  the  mash  as  can  be  seen  from  the  preceding  description, 
does  not  essentially  differ  from  that  to  which  mashes  for  the 
manufacture  of  alcohol  are  subjected.  If,  however,  the  com- 
pletely fermented  "  ripe  "mash  is  to  be  used  for  making  vine- 
gar, it  should  be  subjected  to  a  special  treatment,  the  object  of 
which  is  to  prepare  a  fluid  containing  no  living  yeast. 

By  filtering  the  mash  through  a  closely  woven  linen  cloth 
the  particles  of  malt-husks,  etc.,  are  retained  but  not  the  cells 
of  alcoholic  ferment  which  may  be  present,  and  which,  on  ac- 
count of  their  minuteness,  are  difficult  to  separate  from  the 
fluid  by  filtration.  It  is,  therefore,  best  to  heat  the  mash  be- 
fore filtration  to  about  140°  F.  whereby  the  ferment  is  killed, 


PREPARATION  OF  VINEGAR  FROM  VARIOUS  MATERIALS.       167 

and  at  the  same  time  a  certain  quantity  of  albuminous  sub- 
stances dissolved  in  the  fluid  is  rendered  insoluble  and  sepa- 
rated. The  heating  of  the  mash  is  best  effected  by  passing  it 
through  a  coil  of  tin-pipe  placed  in  a  boiler  filled  with  water 
kept  constantly  boiling.  The  temperature  of  the  fluid  can  be 
readily  regulated  by  increasing  or  decreasing  the  velocity  with 
which  it  passes  through  the  coil.  If  the  fluid  heated  to  140° 
F.  were  allowed  to  cool  in  the  air,  a  large  portion  of  the  alco- 
hol contained  in  it  would  be  lost  by  evaporation,  and  it  is  there- 
fore allowed,  after  heating,  to  pass  through  a  second  coil  of 
pipe  which  is  surrounded  by  cold  water  whereby  it  is  cooled  to 
at  least  86°  F.  This  fluid  is  then  filtered  through  a  linen  bag, 
is  being  repeatedly  poured  back  into  the  filter  until  it  runs  off 
sufficiently  clear.  It  will  not,  however,  be  obtained  perfectly 
clear  in  this  manner,  the  yeast  cells  being  too  minute  to  be  re- 
tained by  such  a  filter,  but  having  been  killed  by  heating,  their 
presence  in  the  fluid  is  connected  with  no  disadvantage. 

By  mixing  the  filtered  fluid  with  from  10  to  15  per  cent,  of 
its  volume  of  vinegar,  an  alcoholic  liquid  is  obtained  which 
can  be  worked  in  the  usual  manner  in  the  quick-process  gen- 
erators, and  yields  an  agreeable  aromatic  vinegar  which  clari- 
fies rapidly  and  improves  byt  storing. 

According  to  the  slow  process,  the  fermented  malt-wort  is 
run  into  casks  placed  in  apartments  called  "  stoves,"  since 
they  are  heated  by  stoves  or  steam  to  a  temperature  ranging 
from  70°  to  80°  F.  The  casks  are  arranged  in  parallel  rows, 
resting  upon  long  wooden  beams  elevated  about  18  inches 
from  the  ground,  and  having  their  bungs  uppermost  while  a 
small  hole  on  top  of  the  front  head  of  each  causes  the  circula- 
tion of  air. 

A  large  saving  of  labor  will  be  effected  by  connecting  ele- 
vated tanks  holding  the  fermented  wort  with  pipes  and  mov- 
able flexible  hose  which  will  allow  of  the  rapid  and  easy  filling 
of  the  casks.  The  vinegar  produced  is  siphoned  off  into  in- 
clined troughs,  which  deliver  it  to  a  central  underground 
tank,  from  which  it  is  pumped  into  the  storing  tanks. 


168  MANUFACTURE    OF    VINEGAR. 

Malt  vinegar  generally  contains  a  great  deal  of  mucilaginous 
matter  which  settles  with  difficulty,  preventing  its  keeping, 
while  giving  nourishment  to  vinegar  eels.  It  is  therefore 
necessary  to  filter  it,  and  for  this  purpose  it  is  pumped  into 
the  refining  or  rape  vessels.  These  vessels  are  often  filled  with 
wood  shavings,  straw,  or  spent  tanner's  wood,  but  nothing  acts 
as  well  in  producing  by  filtration  a  clear  bright  vinegar  as  the 
stalks  and  skins  of  grapes  or  raisins  technically  called  "  rape." 
Where  there  is  power  and  a  large  quantity  of  vinegar  is  man- 
ufactured, the  filtering  is  effected  under  a  considerable  hydro- 
static pressure.  The  rape  is  placed  in  a  closed  vessel  between 
two  false  perforated  bottoms.  A  circuit  of  pipes  is  connected 
at  the  lower  and  upper  part  of  the  vessel,  and  by  means  of  a 
pump  the  vinegar  is  made  to  pass  again  and  again  through 
the  rape. 

The  mode  of  manufacture  is  frequently  effected  by  "  field- 
ing." In  this  case,  as  the  term  implies,  the  process  is  con- 
ducted in  the  open  air.  The  casks  rest  on  small  frames  1J 
feet  high,  being  supported  by  firm  pillars  of  brick-work  or 
wood.  The  operation  generally  begins  in  spring  and  continues 
during  the  summer.  The  fermented  liquor  is  run  into  the 
casks  by  the  bung-holes,  the  latt^fr  being  left  open  in  dry,  and 
loosely  covered  with  a  tile  in  wet  weather.  Gradually  the 
alcohol  of  the  "gyle,"  as  the  fermented  liquor  is  called,  be- 
comes oxidized,  and  acetic  acid  is  produced,  of  course  simul- 
taneously affording  vinegar.  The  latter  is  then  drawn  off  and 
transferred,  to  the  refining  or  rape  vessels  where  it  passes 
through  the  process  of  filtration  already  described. 

In  some  factories  large  quantities  of  sour  ale  and  beer  are 
converted  by  similar  processes  into  vinegar,  but  the  product  is 
much  inferior  to  the  vinegar  made  from  malt-wort.  The  large 
amount  of  nitrogenous  and  other  extractive  substances  which 
those  liquids  contain  undergoes  a  second  or  putrid  fermenta- 
tion after  the  alcohol  has  been  oxidized  into  acetic  acid,  and 
in  doing  so  reacts  upon  the  acid,,  leaving  a  liquid  of  a  dis- 
agreeable odor  slightly  resembling  very  stale  beer.  By  the 


PREPARATION  OF  VINEGAR  FROM  VARIOUS  MATERIALS.       169 

addition  of  sulphuric  acid  this  second  fermentation  is  post- 
poned for  some  time,  but  the  vinegar  has  nevertheless  a 
nauseous  smell  which  renders  it  objectionable. 

Vinegar  from  Sugar-Beets. — The  juice  of  the  sugar-beet  con- 
tains a  considerable  quantity  of  cane-sugar  and  is  readily 
brought  into  alcoholic  fermentation,  so  that  seemingly  this 
root  would  form  a  very  suitable  material  for  the  manufacture 
of  vinegar.  Sugar-beets  contain  on  an  average  12  percent, 
of  cane-sugar,  the  latter  yielding,  when  completely  fermented, 
a  fluid  containing  about  6J  per  cent,  by  weight  of  alcohol ;  a 
fluid  with  this  percentage  of  alcohol  yields  vinegar  with  6  per 
of  acetic  acid. 

In  addition  to  sugar  the  juice  of  the  beet-root  contains, 
however,  a  large  number  of  other  substances  which  exert  an 
influence  upon  the  course  of  alcoholic  fermentation,  and,  be- 
sides alcohol,  a  large  quantity  of  fusel  oils  is  formed,  so  that 
the  alcohol  has  to  be  thoroughly  rectified  before  it  is  fit  for 
use.  The  fermented  beet-root  juice  itself  has,  however,  a  dis- 
agreeable taste  and  odor,  and  the  vinegar  prepared  from  it 
showing  similar  properties  will  not  be  fit  for  household  pur- 
poses until  a  remedy  for  these  drawbacks  is  found.  Numerous 
experiments  made  for  the  purpose  of  freeing  beet-root  vinegar 
from  the  substances  which  impart  to  it  a  disagreeable  odor 
and  taste  have  given  no  favorable  results.  Filtering  through 
charcoal,  and  even  distilling  the  vinegar  and  treating  the  dis- 
tilled product  with  strongly  oxidizing  bodies,  do  not  produce 
the  desired  effect.  From  these  experiments  it  would  seem 
impossible  to  directly  obtain  from  sugar-beets  vinegar  fit  for 
household  use. 

Vinegar  from  Sugar,  Fruits  and  Berries. — By  fermenting 
sugar  solution  with  pure  yeast  and  pouring  off  the  clear  alco- 
holic fluid,  the  latter  shows  a  slightly  acid  reaction  (from  suc- 
cinic  acid),  but  is  not  converted  into  vinegar  even  if  standing 
for  several  weeks  in  the  most  suitable  temperature,  because 
the  vinegar  ferment  is  wanting.  By  adding,  however,  an 
excess  of  yeast,  so  that  it  remains  partially  suspended  in  the 


170  MANUFACTURE    OF    VINEGAR. 

fluid,  which  can  be  effected  by  the  addition  of  solution  of  gum 
or  starch  paste,  the  nourishment  for  the  spores  of  the  vinegar 
ferment  reaching  the  fluid  from  the  air  is  provided  and 
acetification  takes  place. 

Cadet-Gassicourt  advises  the  fermentation  together  of  124 
parts  of  sugar,  868  of  water,  and  80  of  yeast,  and  to  filter  after 
one  month.  Or,  according  to  another  formula :  Sugar  245 
parts,  gum  61,  water  2145,  yeast  20.  Allow  to  ferment  at 
68°  F.  Fermentation  begins  the  same  day  and  is  completed 
in  15  days. 

Doebereiner  gives  the  following  directions  :  Dissolve  10  Ibs. 
of  sugar  in  180  quarts  of  hot  water,  add  6  Ibs.  of  pulverized 
crude  tartar  (it  dissolves  only  partially),  and  after  .cooling  to 
77°  F.  induce  fermentation  by  4J  quarts  of  beer  yeast.  In 
about  eight  days,  when  fermentation  is  finished,  add  about  15 
quarts  of  spirits  of  wine  of  at  least  50  per  cent.  Tr.  or  8  quarts 
of  alcohol  of  90  per  cent.  Tr.,  and  bring  the  mixture  into  the 
acetifying  vessel.  This  fluid  would  also  be  suitable  for  the 
quick  process. 

For  making  vinegar  on  a  small  scale  for  domestic  use,  brown 
sugar  with  water  alone,  or  sugar  with  raisins,  currants,  and 
especially  ripe  gooseberries,  may  be  used.  These  should  be 
mixed  in  the  proportion  which  would  give  a  strong  wine,  put 
into  a  small  barrel  filled  to  about  three-fourths  of  its  capacity, 
and  bunged  very  loosely.  Some  yeast  should  be  put  in  and 
the  barrel  set  in  the  sun  in  summer  or  a  little  way  from  the 
fire  in  winter,  and  fermentation  will  soon  begin.  This  should 
be  kept  up  constantly,  but  moderately,  till  the  taste  and  smell 
indicate  that  the  vinegar  is  complete.  It  should  then  be 
poured  off  clear,  and  bottled  carefully.  It  will  keep  much 
better,  if  it  is  boiled  for  a  minute,  cooled,  and  strained  before 
bottling. 

With  the  exception  of  apples  and  pears,  the  different  varie- 
ties of  fruit  cannot  be  had  in  such  abundance  as  that  they 
could  be  used  for  the  manufacture  of  vinegar  on  a  large  scale, 
and  hence  only  a  brief  description  of  their  utilization  for  that 
purpose  will  be  given. 


PREPARATION  OF  VINEGAR  FROM  VARIOUS  MATERIALS.       171 

It  is  characteristic  of  most  of  our  varieties  of  fruits,  and 
especially  of  berries,  that  in  proportion  to  their  content  of 
sugar  they  have  a  much  greater  content  of  free  acids  than 
grapes,  and  this  circumstance  must  be  taken  into  considera- 
tion, as  otherwise  wine  would  be  obtained  which  contains  a 
considerable  quantity  of  unfermented  sugar.  The  following 
table  shows  the  average  content  of  sugar  and  free  acid  in  the 
most  common  varieties  of  fruits  : — 

Free  acid  calculated 
Sugar.  as  malic  acid. 

Cherries   .    .    ;;„    . 10.00 

Apples 6.25  to  13.99  0.691 

Pears .  .    .    ....    .'  .    .    .    .    .    .  8.78 

Currants 6.40  2.147 

Strawberries.  .'..':..   .    .    •  .    .    .    .  5.09  to  11.31  '    1.363 

Gooseberries    .    .  -    .  ,< 6.93  1.603 

Bilberries..        .    .    .V.*.;:.V.  5.78  1.341 

Raspberries  .  .    : ".    ......  '..  4.02  1.484 

Blackberries    .    .......    .    .  4.44  1.188 

According  to  the  above  table,  currants,  gooseberries,  rasp- 
berries, etc.,  contain  on  an  average  scarcely  6  per  cent,  ol 
sugar,  and  consequently  their  juice,  after  complete  fermenta- 
tion, would  give  a  fluid  with  about  3  per  cent,  of  alcohol,  from 
which  vinegar  with  about  2J  per  cent,  of  acetic  acid  could  be 
obtained.  Such  vinegar  being,  however,  too  weak,  those  ber- 
ries would  not  seem  suitable  for  the  direct  preparation  of  vine- 
gar. Moreover,  the  complete  fermentation  of  the  juice  of  most 
berries  is  very  difficult,  the  free  acids,  among  which  malic  acid 
preponderates,  exerting  an  injurious  influence  upon  the  pro- 
gress of  fermentation. 

Vinous  fluids  of  an  agreeable  taste  can,  however,  be  pre- 
pared from  berries,  and  from  them  an  aromatic  and  finely 
flavored  vinegar,  by  decreasing  the  content  of  acid  in  the  juice 
and  increasing  that  of  sugar.  The  juice  of  currants,  as  seen 
from  the  above  table,  contains  in  round  numbers  6  per  cent, 
of  sugar  and  2  per  cent,  of  malic  acid.  By  diluting  this  juice 
with  an  equal  volume  of  water  a  fluid  containing  3  per  cent. 


172  MANUFACTURE    OF    VINEGAR. 

of  sugar  and  1  per  cent,  of  acid  is  obtained,  and  the  content 
of  the  former  can  be  increased  at  will  by  the  direct  addition 
of  sugar. 

By  compounding,  for  instance,  100  quarts  of  currant  juice 
with  100  quarts  of  water  and  adding  34  Ibs.  of  sugar,  the  re- 
sulting fluid  contains  about  20  per  cent,  of  sugar  and  after 
complete  fermentation  gives  a  fluid  with  about  9.5  per  cent,  of 
alcohol,  which  yields  vinegar  of  nearly  9  per  cent,  strength. 
The  taste  of  this  vinegar  is,  however,  stronger  and  more  agree- 
ably acid  than  that  of  vinegar  from  alcohol,  it  containing  be- 
sides acetic  acid  about  1  per'  cent,  of  malic  acid.  Moreover, 
vinegar  obtained  from  berries  contains  a  certain  quantity  of 
extractive  substances  and  odoriferous  products  of  fermentation, 
so  that  it  possesses  an  agreeable  bouquet  and  thus  appears 
more  valuable  than  the  ordinary  product. 

In  many  regions  bilberries  grow  in  abundance  and  can  be 
bought  very  cheap.  Treated  in  the  above  manner,  they  yield 
an  excellent  vinegar,  possessing,  however,  a  somewhat  harsh 
by-taste,  due  to  the  tannin  contained  in  the  berries.  The  latter 
can  be  removed  from  the  fermented  fluid  before  using  it  for 
the  preparation  of  vinegar,  by  compounding  the  latter  when 
quite  clear  with  gelatine  solution  or  fresh  white  of  egg,  both 
forming  insoluble  combinations  with  the  tannin,  which  sepa- 
rates in  the  form  offtakes. 

In  regard  to  the  preparation  of  vinegar  from  berries,  it  re- 
mains to  be  remarked  that,  after  pressing  the  bruised  berries, 
the  juice  is  compounded  with  water  and  sugar  and  at  once 
brought  into  fermentation  by  the  addition  of  yeast  (best  fresh 
wine-yeast,  or  if  this  be  wanting,  compressed  yeast  divided 
in  water).  Fermentation  should  take  place  at  quite  a  high 
temperature,  68°  to  72°  F.  The  separated  yeast  is  carefully 
removed  from  the  fermented  liquid  and  the  latter  stored  away 
in  barrels  kept  constantly  filled  up  to  the  bung,  or  at  once  used 
for  the  preparation  of  vinegar.  By  converting  fruit-wine  into 
vinegar  by  means  of  the  vinegar  ferment  floating  upon  the 
fluid  a  much  finer  product  is  obtained  than  by  the  quick 
process. 


PREPARATION  OF  VINEGAR  FROM  VARIOUS  MATERIALS.       173 

Peaches  as  Vinegar  Stock.  Mr.  H.  C.  Gore  *  has  made  ex- 
periments regarding  the  value  of  peaches  as  vinegar  stock. 
The  conclusions  drawn  by  him  from  this  work  are,  first,  that 
peaches  contain  sufficient  fermentable  sugar  for  use  as  vinegar 
stock,  and,  second,  that  they  can  be  successfully  handled  by 
machinery  already  in  use  for  making  apple  cider  and  vinegar. 
Other  points  of  interest  are  as  follows  :  First,  but  little  varia- 
tion was  found  in  the  composition  of  the  same  variety  of 
peaches  when  obtained  from  different  localities.  Second,  the 
peach  juices  analyzed  were  found  to  be  richer  in  sugar  than 
those  which  have  been  previously  analyzed  by  others,  but 
they  were  about  1  per  cent  lower  in  sugar  than  average  apple 
juices.  They  were  considerably  richer  than  apples  in  suc- 
rose and  in  acid.  Third,  it  was  found  that  the  use  of  pure 
culture  yeasts  was  not  necessary  to  insure  rapid  alcoholic  fer- 
mentation. Fourth,  the  ciders  prepared  from  peaches  were 
considerably  poorer  in  alcohol  than  apple  ciders  on  Account  of 
the  fact  that  peaches  contain  less  total  sugars  than  apples. 
Fifth,  the  presence  of  brown  rot  was  found  not  to  inter- 
fere with  the  alcoholic  fermentation  of  the  ground  peaches, 
but  a  large  proportion  of  the  sugars  was  wasted  by  allowing 
the  fruit  to  rot  before  fermenting.  Sixth,  well-flavored  vine- 
gars were  produced  by  the  use  of  a  small  quick-process  gener- 
ator. These  vinegars  were  of  acceptable  quality,  though  tur- 
bid, and  did  not  possess  the  distinctive  peach  flavor. 

Cider  Vinegar.  The  manufacture  of  cider  itself  will  be  de- 
scribed in  another  portion  of  this  work  and,  hence,  its  utiliza- 
tion for  the  preparation  of  vinegar  will  here  only  be  given. 

The  preparation  of  vinegar  from  good  cider  is  not  difficult, 
the  process  of  acetification  by  means  of  the  vinegar  ferment 
floating  upon  the  surface  yielding  an  aromatic  product  of  a 
fine  flavor  which  is  nearly  of  as  good  a  quality  as  wine  vine- 
gar. On  account  of  its  content  of  malic  acid,  the  vinegar  is 

*  United  States  Department  of  Agriculture,  Bureau  of  Chemistry — Circular 
No.  51. 


174  MANUFACTURE    OP    VINEGAR. 

more  acid  than  ordinary  vinegar  with  the  same  content  of 
acetic  acid.  But  in  order  to  produce  cider  vinegar  of  the  first 
quality  one  must  have  good  cider  ;  vinegar  made  of  watered 
cider  will  be  thin  and  weak. 

The  cider  extracted  by  the  first  pressing  of  the  apples  is 
but  in  rare  cases  used  for  making  vinegar,  the  juice  obtained 
by  subjecting  the  pomace,  with  the  addition  of  water  or  sugar 
solution,  to  a  second  and  third  pressure  being  as  a  rule  utilized 
for  the  purpose.  The  juice  thus  obtained  should  be  so  consti- 
tuted as  to  yield  vinegar  containing  4  J  to  5 \  per  cent,  of  acetic 
acid.  The  cider  to  be  converted  into  vinegar  should  be  as 
clear  as  possible  and,  if  necessary,  filtration  over  sand  or  storing 
for  some  time  is  advisable. 

The  conversion  of  cider  into  vinegar  is  best  effected  in  a 
generator  furnished  with  a  tilting  trough  for  the  intermittent 
supply  of  cider. 

After  the  cider  has  been  extracted  and  the  cheese  removed 
from  the  press,  the  pomace  may  also  be  utilized  for  making 
vinegar  by  treating  it  as  follows :  The  pomace  is  piled  up  on 
a  platform  of  suitable  construction  and  allowed  to  ferment. 
In  the  course  of  a  few  days  considerable  heat  will  be  devel- 
oped, when  a  few  pailfuls  of  warm  water  (not  boiling)  are 
poured  upon  the  pile,  and  in  the  course  of  twenty-four  hours 
the  pomace  will  be  in  proper  condition  for  grinding.  It  is 
then  run  through  a  grater-mill  and  relaid  upon  the  press  in  a 
cheese  in  tlpe  same  manner  as  originally  laid  in  cider  making. 
It  is  then  subjected  to  heavy  pressure  until  the  liquid  con- 
tained in  the  cheese  is  extracted.  This  liquid  may  be  ex- 
posed in  shallow  open  casks  in  a  warm  room,  and  in  a  short 
time  will  be  found  good  vinegar ;  or  it  may  be  immediately 
passed  through  a  generator. 

Mr.  Walter  G.  Sackett  *  gives  directions  for  home-made  cider 
vinegar  as  follows  :  "  The  sweet  cider  as  it  comes  from  the 

*  Bulletin  192,  November,  1913.  The  Agricultural  Experiment  Station  of  the 
Colorado  Agricultural  College. 


PREPARATION  OF  VINEGAR  FROM  VARIOUS  MATERIALS.       175 

press  may  either  be  placed  at  once  in  barrels,  which  should 
not  be  filled  more  than  two-thirds  or  three-fourths  full,  or  if 
one  has  suitable  wooden  tubs  or  vats,  in  a  clean,  cool  place ; 
it  may  be  stored  there  from  12  to  24  hours  to  permit  settling, 
after  which  it  should  be  transferred  to  barrels.  The  bung 
should  be  left  out  and  a  loose  stopper  of  cotton  batting  in- 
serted in  the  hole  to  decrease  evaporation  and  prevent  dirt 
from  falling  in.  The  barrels  should  not  be  tightly  stoppered 
until  the  vinegar  contains  at  least  4  to  5  per  cent,  of  acetic 
acid,  at  which  time  they  should  be  filled  entirely  full  and 
securely  bunged.  Throughout  the  entire  period  of  vinegar 
making,  the  casks  should  be  placed  on  their  side  and  not  on 
the  end.  This  gives  the  cider  a  larger  free  surface  exposed  to 
the  air,  which  is  quite  essential  to  rapid  vinegar  formation. 
It  may  also  be  of  some  advantage  in  admitting  air  to  bore  a 
If  inch  hole  in  each  end  of  the  barrel  along  the  upper  edge. 
If  this  is  done,  the  holes  should  be  covered  with  fine  gauze 
wire  or  two  thicknesses  of  cheese-cloth  to  exclude  small 
vinegar  flies. 

"  A  few  days  after  the  cider  is  put  into  the  barrels  the  char- 
acteristic frothing  appears  at  the  bung-hole.  To  use  a  com- 
mon expression,  'it  is  beginning  to  work.'  This  indicates 
that  the  alcoholic  fermentation,  the  first  step  in  the  vinegar- 
making  process,  has  begun,  and  the  sugar  of  the  apple  juice  is 
being  converted  into  alcohol  and  carbon  dioxide  gas.  To  de- 
pend upon  the  wild  yeast  of  the  air  to  accomplish  the  fermen- 
tation is  too  uncertain  since  many  of  them  are  able  to  convert 
only  a  small  part  of  the  sugar  into  alcohol,  while  others  act 
so  slowly  that  they  are  impracticable.  Inasmuch  as  the  per- 
centage of  acetic  acid  in  the  vinegar  depenjds  directly  upon  the 
amount  of  alcohol  produced,  it  is  very  essential  to  secure  as 
large  a  yield  of  alcohol  as  possible  from  the  sugar  present. 
This  means  converting  all  of  the  sugar  into  alcohol  in  the 
shortest  time  possible.  The  most  satisfactory  way  of  doing 
this  is  to  add  one  cake  of  compressed  yeast,  stirred  up  in  a 
little  cooled,  boiled  water,  to  each  five  gallons  of  sweet  cider. 


176  MANUFACTURE    OF    VINEGAR. 

In  place  of  this,  one  quart  of  liquid  wine  yeast,  propagated 
from  a  pure  culture,  may  be  used  for  each  thirty  gallons  of 
cider. 

"  During  the  alcoholic  fermentation,  the  cider  should  be 
kept  at  a  temperature  of  05°  to  80°  F.  Here  is  where  many 
make  the  very  serious  mistake  of  putting  their  fresh  cider  into 
a  cool  cellar  where  the  fermentation  takes  place  entirely  too 
slowly.  If  the  cider  is  made  in  the  fall,  the  barrels  should  be 
left  out  of  doors  for  a  while  on  the  protected,  sunny  side  of  a 
building  and  kept  warm,  unless  a  regular  vinegar-cellar,  arti- 
ficially heated,  is  at  hand. 

"  If  yeast  is  added  and  the  proper  temperature  is  maintained, 
the  alcoholic  fermentation  should  be  completed  in  six  weeks 
to  three  months  in  place  of  seven  to  ten  months  as  in  the  old- 
fashioned  way.  Experiments  along  this  line  have  shown  that 
when  yeast  is  added  and  a  temperature  of  70°  F.  is  held,  the 
cider  at  the  end  of  one  month  contained  7.25  per  cent,  of  alco- 
hol as  against  .11  per  cent,  when  no  yeast  was  used  and  the 
temperature  was  between  45°  and  55°  F.  Cider  kept  in  a 
cellar  at  45°  to  55°  F.  with  no  yeast  added  required  seven 
months  to  make  6.79  per  cent,  of  alcohol. 

" Temperature,  alone,  is  an  important  factor  as  shown  by 
an  experiment  wherein  cider  to  which  no  yeast  was  added  was 
held  for  three  months  at  70°  F.  and  yielded  6.41  per  cent,  of 
alcohol. 

"There  is  no  question  but  that  the  time  required  for  com- 
pleting the  alcoholic  fermentation  can  be  reduced  at  least  one- 
half  by  adding  yeast  and  by  maintaining  the  proper  tempera- 
tures. By  hastening  this  operation,  the  loss  of  alcohol  by 
evaporation  is  reduced,  and  the  acetic  fermentation  can  be 
started  that  much  sooner. 

"  As  soon  as  alcoholic  fermentation  is  completed  draw  off 
the  clear  liquid,  being  very  careful  not  to  disturb  the  sedi- 
ment in  the  barrel.  Wash  out  the  barrel  thoroughly  and  re- 
place the  hard  cider.  It  is  believed  that  removing  this  sedi- 
ment permits  the  acetic  acid  to  form  somewhat  more  quickly, 


PREPARATION  OF  VINEGAR  FROM  VARIOUS  MATERIALS.       177 

and  furthermore,  the  sediment  may  undergo  decomposition 
and  impart  a  disagreeable  flavor  to  the  cider.  Again  these 
dregs  may  harbor  living  bacteria  which  either  destroy  acetic 
acid  or  interfere  with  its  formation. 

"  We  are  now  ready  to  introduce  the  acetic  acid  germs. 
This  ma}7  be  carried  on  in  a  number  of  different  ways,  but 
preferably  by  means  of  a  pure  culture  of  a  desirable  organism 
which  has  been  selected  because  of  its  ability  to  produce  strong 
acetic  acid  and  impart  an  agreeable  flavor  to  the  vinegar.  In 
place  of  the  pure  culture  starter,  one  may  add  two  to  four 
quarts  of  good  cider  vinegar  containing  more  or  less  '  mother  ' 
for  each  barrel.  The  introduction  of  a  desirable  organism  is 
left  to  chance  in  this  case.  A  serious  objection  to  the  latter 
method  is  that  sometimes  one  introduces  foreign  organisms 
with  the  '  mother'  which  may  prove  detrimental  to  the  vine- 
gar. Pure  culture  *  is  free  from  this  objection. 

"  With  the  acetic  fermentation,  as  with  the  alcoholic,  the 
higher  temperatures  favor  the  changes.  Experimental  work 
shows  that  hard  cider  to  which  no  acetic  acid  bacteria  were 
added  other  than  those  that  came  from  the  air,  and  kept  at 
65°  F.,  when  six  months  old,  contained  7.03  per  cent,  of  acetic 
acid,  while  that  held  at  55°  F.  showed  only  3.63  per  cent. 

"  The  addition  of  some  kind  of  an  acetic  acid  starter,  either 
as  a  pure  culture  of  the  acetic  organism  or  as  good  vinegar, 
hastens  the  fermentation  and  reduces  appreciably  the  time 
required  for  making  marketable  vinegar. 

"  For  most  satisfactory  results  we  would  recommend  using 
the  pure  cultures  and  holding  the  vinegar  at  a  temperature  of 
65  to  75°  F.  Under  these  conditions,  salable  vinegar  can  be 
obtained  in  three  to  six  months  in  place  of  two  to  three  years, 
as  is  often  the  case.  Theoretically,  100  parts-  of  alcohol  should 
give  about  130  parts  of  acetic  acid,  but  in  actual  practice  this 
will  probably  fall  below  120. 

*  The  pure  cultures,  both  of  yeast  and  acetic  acid  bacteria,  for  vinegar  making, 
here  referred  to,  can  be  obtained  by  addressing  The  Bacteriological  Department, 
Experimental  Station,  Fort  Collins,  Colorado. 
12 


178  MANUFACTURE    OF* VINEGAR. 

"  When  the  acetic  acid  has  reached  4.5  to  5  per  cent.,  fill 
the  barrels  as  full  as  possible  and  cork  tightly.  In  this  way, 
contact  of  the  air  with  the  vinegar  is  cut  off  and  the  acetic 
acid  organisms  soon  cease  their  activity.  If  this  is  not  done 
and  the  acetic  and  other  bacteria  are  allowed  to  develop  in- 
definitely, there  is  apt  to  be  a  reverse  reaction  resulting  in  a 
partial  or  complete  loss  of  the  acetic  acid.  Such  vinegar  is, 
of  course,  worthless." 


CHAPTER  XVII. 

VINEGAR    SPECIALTIES. 

THESE  specialties  may  be  divided  into  two  groups :  Into 
those  with  a  specific  odor,  and  those  with  a  specific  odor  and 
taste.  As  an  example  for  both  kinds  tarragon  vinegar  may 
be  taken.  If  it  is  prepared  by  simply  dissolving  in  the  vine- 
gar the  volatile  oil  of  dragon's  wort  (Artemisia  dracunculus)  ob- 
tained by  distillation  with  water,  the  product  is  simply  per- 
fumed vinegar,  the  odor  of  the  volatile  oil  being  mixed  with 
that  of  the  acetic  acid,  but  the  taste  remains  unchanged.  If, 
however,  the  fresh  leaves  of  the  plant  are  macerated  with  vine- 
gar, not  only  the  volatile  oil  is  dissolved,  but  also  certain  ex. 
tractive  substances  peculiar  to  this  plant,  and  the  taste  of  the 
vinegar  is  also  changed,  the  product  in  this  case  being  aro- 
matized vinegar. 

By  dissolving  in  vinegar  rose  oil  or  rose  water  (perfumed), 
rose  vinegar  is  obtained.  By  treating  raspberries  with  vinegar 
the  latter  absorbs  not  only  the  odoriferous  substances  of  the 
raspberry,  but  also  the  non-odoriferous  extractive  substances, 
and  the  product  is  aromatized  vinegar. 

By  skillful  manipulation  every  volatile  oil  can  be  dissolved 
in  vinegar,  and  consequently  as  many  different  varieties  of 
perfumed  vinegar  can  be  prepared  as  there  are  volatile  oils. 


VINEGAR    SPECIALTIES.  179 

In  fact,  perfumers  prepare  a  number  of  such  varieties  which 
contain  one  or  more  volatile  oils  whose  odors  harmonize  and 
are  sold  as  volatile  spirit  of  vinegar,  fumigating  vinegar,  etc. 
Such  vinegars  can  be  prepared  in  various  ways,  the  finest  odors 
being,  however,  obtained  by  distilling  the  fresh  parts  of  the 
plants  with  water  and  mixing  the  distillate,  which  actually 
represents  a  solution  of  the  volatile  oil  in  water,  with  strong 
vinegar.  The  finest  rose  vinegar,  orange  blossom  vinegar, 
etc.,  are  prepared  in  this  manner. 

For  this  rather  tedious  process  of  preparing  perfumed  vine- 
gar, the  one  in  which  freshly  prepared  volatile  oils  are  used 
may  be  advantageously  substituted.  Td  be  sure  the  volatile 
oils  dissolve  only  sparingly  in  vinegar,  but  sufficiently  so  to 
impart  their  characteristic  odor  to  it.  By  using  an  excess  of 
volatile  oil  it  does  not  dissolve;  but  distributes  itself  in  fine 
drops  throughout  the  vinegar,  rendering  the  latter  opalescent, 
so  that  fining  with  tannin  and  isinglass  is  necessary  to  make 
it  bright  again. 

This  drawback  can  be  avoided  by  a  simple  manipulation 
which  is  based  upon  the  fact  that  a  body  dissolving  with  diffi- 
culty dissolves  the  more  readily  the  greater  surface  it  offers  to 
the  solvent. 

Prepare  glass-powder  as  fine  as  the  best  wheat  flour  by  heat- 
ing pieces  of  glass,  throwing  them  into  cold  water,  and  pulver- 
izing and  elutriating  in  a  mortar.  By  the  sudden  cooling  the 
glass  becomes  so  brittle  that  it  can  be  readily  converted  into  a 
fine  powder.  Bring  a  suitable  quantity  of  this  powder  into  a 
porcelain  dish  and  drop  volatile  oil  upon  it  with  constant  rub- 
bing until  it  is  uniformly  moistened.  Pour  the  vinegar  to  be 
perfumed  upon  this  glass  powder  and  stir  gently  with  the 
pestle.  The  fluid  is  then  poured  into  the  barrel  intended  for 
the  reception  of  the  perfumed  vinegar  and  a  fresh  quantity  of 
vinegar  poured  upon  the  glass-powder,  this  being  continued 
until  all  the  glass-powder  has  been  brought  into  the  barrel  by 
stirring  and  pouring  over  fresh  vinegar.  The  barrel  is  then 
entirely  filled  with  vinegar,  and  after  being  securely  bunged, 


180  MANUFACTURE    OF    VINEGAR. 

rolled  in  order  to  secure  a  uniform  mixture  of  its  contents. 
It  is  then  allowed  to  rest  for  a  few  days  for  the  glass-powder 
to  settle.  The  entirely  clear  perfumed  vinegar  is  then  drawn 
off  into  bottles,  which  are  to  be  kept  in  a  dark  cool  room,  the 
odor  of  the  volatile  oil  being  injured  by  light  and  heat. 

For  the  preparation  of  volatile  fumigating  or  toilet  vinegars 
it  is  best  to  dissolve  the  volatile  oils  in  uncolored  vinegar  pre- 
pared from  alcoholic  liquid.  Where  the  remaining  of  a  small 
residue  after  the  volatilization  of  the  perfumed  vinegar  is  of 
no  importance,  pulverized  sugar  may  be  substituted  for  the 
glass-powder,  as  it  acts  in  the  same  manner ;  the  only  differ- 
ence is  that  the  glass-powder  being  an  insoluble  body  falls  to 
the  bottom  of  the  barrel,  while  the  sugar  dissolves  together 
with  the  volatile  oil  in  the  vinegar. 

By  the  above-described  process  perfumed  vinegar  with  the 
odor  of  dragoii's-wort,  peppermint,  anise,  rose,  etc.,  etc.,  may 
be  prepared,  and  by  a  suitable  mixture  of  those  whose  odors 
harmonize,  a  great  number  of  fumigating  and  toilet  vinegars 
may  be  obtained. 

The  preparation  of  aromatized  vinegars  by  means  of  the  ex- 
tractive substances  of  plants  is  very  simple.  The  parts  of 
plants  to  be  extracted  are  placed  in  a  suitable  vessel,  a  barrel 
or  large  flask,  and  after  pouring  vinegar  over  them  and  closing 
the  vessel,  are  allowed  to  rest  for  a  few  weeks  in  a  moderately 
warm  room.  In  case  glass  vessels  are  used  they  have  to  be 
kept  in  a  dark  room,  light  exerting  an  injurious  influence  upon 
the  odors.  The  vegetable  substances  used  for  aromatizing 
vinegar  containing,  as  a  rule,  a  large  quantity  of  water,  strong 
vinegar,  with  10  to  11  per  cent,  acetic  acid,  should  be  used. 

Below  a  few  formulas  for  toilet  and  table  vinegars  are  given  : 

TOILET  VINEGARS. 

Mohr's  Volatile  Spirits  of  Vinegar. — Equal  parts  of  acetic  acid 
and  acetic  ether,  perfumed  with  a  few  drops  of  oil  of  cloves. 

Aromatic  Vinegar. — Concentrated  acetic  acid  8  ounces,  oil  of 
lavender  2  drachms,  oils  of  rosemary  and  cloves  each  1 
drachm,  oil  of  camphor  1  ounce. 


VINEGAR    SPECIALTIES.'  181 

Bruise  the  camphor  and  dissolve  it  in  the  acetic  acid,  then 
add  the  perfumes ;  after  standing  for  a  few  days  with  occa- 
sional agitation  it  is  strained  and  ready  for  use. 

Henry's  Vinegar. — Dried  leaves  of  rosemary,  rue,  worm- 
wood, sage,  mint  and  lavender  flowers  each  1  ounce,  bruised 
nutmeg,  cloves,  angelica  root  and  camphor  each  J  ounce,  alco- 
hol (rectified)  8  ounces,  concentrated  acetic  acid  32  ounces. 

Macerate  the  materials  for  a  day  in  the  alcohol ;  then  add 
the  acid  and  digest  for  a  week  longer  at  a  temperature  of 
about  59°  F.  Finally  press  out  the  now  aromatized  vinegar 
.and  filter  it. 

Vinaigre  des  Quatre  Voleurs. — Fresh  tops  of  common  worm- 
wood, Roman  wormwood,  rosemary,  sage,  mint  and  rue  each 
}  ounce,  lavender  flowers  1  ounce,  garlic,  calamus  aromaticus, 
cinnamon,  cloves,  and  nutmeg  each  1  drachm,  camphor  J 
ounce,  alcohol  or  brandy  1  ounce,  strong  vinegar  4  pints. 

Digest  all  the  materials,  except  the  camphor  and  spirit,  in 
a  closely  covered  vessel,  for  a  fortnight,  at  summer  heat ;  then 
express  and  filter  the  vinegar  produced  and  add  the  camphor 
previously  dissolved  in  the  brandy  or  alcohol. 

Hygienic  or  Preventive  Vinegar. — Brandy  1  pint,  oils  of  cloves 
and  lavender  each  1  drachm,  oil  of  marjoram  J  drachm,  gum 
benzoin  1  ounce. 

Macerate  these  together  for  a  few  hours,  then  add  2  pints  of 
brown  vinegar  and  strain  or  filter. 

Cosmetic  Vinegar. — Alcohol  1  quart,  gum  benzoin  3  ounces, 
concentrated  aromatic  vinegar  1  ounce,  balsam  of  Peru  1 
ounce,  oil  of  neroli  1  drachm,  oil  of  nutmeg  J  drachm. 

TABLE    VINEGARS. 

Anise  Vinegar. — Convert  into  a  coarse  powder  anise  seed  5 
parts,  caraway  seed  f,  fennel  and  coriander  seed  each  J,  pour 
5  parts  of  alcohol  and  45  parts  of  strong  vinegar  over  the 
powders,  close  the  vessel  air-tight  and  let  the  whole  digest  in 
a  warm  place  for  6  to  8  days,  shaking  frequently.  Then  strain 
the  liquid  off,  press  out  the  residue,  filter  the  vinegar,  and  put 
it  up  in  bottles. 


182  MANUFACTURE  OF  VINEGAR. 

Anchovy  Vinegar. — Reduce  1  pound  of  boned  anchovies  to  a 
pulp  in  a  mortar  and  pass  the  mass  through  a  hair-sieve.  The 
bones  and  parts  which  do  not  pass  through  the  sieve  are 
boiled  for  15  minutes  in  a  pint  of  water  and  strained.  To  the 
strained  liquor  add  2J  ounces  of  salt  and  the  same  quantity 
of  flour  together  with  the  pulped  anchovies,  and  allow  the 
whole  to  simmer  for  3  or  4  minutes ;  as  soon  as  the  mixture 
is  cold  add  J  pint  of  strong  vinegar. 

Tarragon  Vinegar. — Pick  the  young  tender  leaves  of  dragon's- 
wort  (Artemisia  dracunculus)  when  the  first  flower-buds  ap- 
pear. Bruise  the  leaves,  place  them  in  a  suitable  vessel,  pour 
good  wine-vinegar  over  them,  and  let  the  whole  stand  for  a 
few  days.  Then  strain  the  vinegar  through  a  cloth,  filter  and 
bottle.  The  bottles  must  be  filled  entirely  full,  as  otherwise 
the  vinegar  will  not  keep. 

Compound  Tarragon  Vinegar. — Comminute  leaves  of  dragon's- 
wort  100  parts,  common  bean  leaves  25,  leaves  of  basil  and 
marjoram  each  12J,  bay  leaves  and  orris  root  each  25,  cloves 
3J,  cinnamon  6J,  and  shallots  25.  Put  all  in  a  suitable  ves- 
sel, pour  700  to  750  parts  of  pure,  strong  vinegar  over  it,  let 
it  stand  in  a  warm  place  and  digest  5  or  6  days,  frequently 
agitating  it.  Then  strain  the  vinegar  through  linen,  press 
out  the  residue,  add  25  parts  of  alcohol,  and  filter.  Keep  the 
vinegar  in  well-corked  bottles  in  a  cool,  dark  place. 

Effervescing  Vinegar. — Dissolve  500  parts  of  loaf  sugar  in 
5000  parts  of  water,  add  lemon  juce  and  rind  cut  up  in  the 
proportion  of  1  lemon  to  1  Ib.  of  sugar,  1J  parts  of  the  best 
cinnamon,  and  12  parts  of  beer  yeast  thoroughly  washed. 
Place  the  whole  in  a  barrel,  and  after  agitating  it  thoroughly 
let  it  ferment  at  a  temperature  of  55°  to  60°  F.  When  fer- 
mentation has  ceased  the  vinous  fluid  is  strained  and  mixed 
with  1000  parts  of  best  wine- vinegar,  previously  boiled  up,  and 
yeast  in  the  proportion  of  1  spoonful  to  5  Ibs.  of  sugar.  The 
fluid  is  then  distributed  in  several  earthenware  pots  and  ex- 
posed to  a  temperature  of  77°  to  88°  F.  until  it  has  been  con- 
verted into  strong  vinegar.  This,  while  remaining  in  the  pots, 


VINEGAR    SPECIALTIES.  183 

is  mixed  with  200  parts  of  French  brandy  and  after  two  days 
bottled  in  small  bottles.  To  each  pound  of  this  vinegar  are 
added,  f  part  of  crystallized  tartaric  acid,  pulverized,  and  J 
part  of  bicarbonate  of  soda.  The  bottles,  as  soon  as  the  re- 
spective portion  of  the  mixture  has  been  added  to  each,  must 
be  corked  as  quickly  as  possible  and  then  stored  in  a  cool 
place. 

Herb  Vinegar. — Chop  fine  the  leaves  of  marjoram  and  thyme 
each  13J  parts,  common  bean  leaves  6J,  leaves  of  mint,  basil 
and  celery  each  3  J,  and  fresh  shallots  1 J.  Pour  600  or  700 
parts  of  good  vinegar  over  the  herbs  and  treat  in  the  same 
manner  as  given  for  compound  tarragon  vinegar. 

Pine-apple  vinegar. — This  excellent  vinegar  soon-  loses  its 
flavor,  and  it  is  therefore  best  to  prepare  a  small  quantity  at 
a  time  and  keep  in  bottles  closed  air-tight. 

Bruise  the  slices  of  pine-apple  and  pour  over  them  a  con- 
siderable quantity  of  vinegar.  Close  the  vessel  air-tight  and 
let  it  stand  12  hours  ;  then  pour  off  the  vinegar  and  filter. 

Celery  Vinegar. — Celery  seed  4J  ozs.,  vinegar  1  pint.  Digest 
14  days ;  filter. 

Clove  Vinegar. — Cloves  3J  ozs.,  vinegar  1  pint.  Digest  7 
days  and  strain. 

Mustard  Vinegar. — Black  mustard  seed  2  ozs.,  vinegar  1 
pint.  Digest  one  week  and  filter. 

Lovage  Vinegar. —  Lovage  root  2  ozs.,  lovage  seed  1  oz., 
vinegar  10  ozs.  Digest  one  week  and  filter. 

Raspberry  Vinegar. — For  the  preparation  of  this  vinegar  it 
is  best  to  use  the  residue  remaining  after  pressing  the  ripe  and 
crushed  berries,  as  it  contains  sufficent  aroma  to  impart  to 
vinegar  macerated  with  it  for  some  time  an  agreeable  odor 
and  taste  of  raspberries.  However,  the  juice  may  also  be 
used,  but  if  the  vinegar  itself  is  not  very  strong  it  becomes 
thereby  too  much  diluted  and  consequently  weak. 

Crush  the  fresh  berries  to  a  paste  and  allow  the  latter  to 
stand  a  few  days,  stirring  it  frequently,  for  the  small  quantity 
of  sugar  contained  in  the  berries  to  ferment.  By  the  alcohol 


184  MANUFACTURE    OF    VINEGAR. 

thus  formed  the  pectin  in  the  juice  is  to  a  great  extent  sepa- 
rated. The  paste  is  then  brought  into  a  small  bag  and 
pressed. 

The  press-cake  is  crushed,  made  into  paste  with  vinegar 
and  spread  out  flat,  exposed  to  the  air  for  a  few  days,  being 
frequently  stirred.  During  this  time  the  paste,  at  first  pale 
red,  again  acquires,  in  consequence  of  a  process  of  oxidation, 
a  vivid  red  color.  The  quantity  of  vinegar  required  is  then 
poured  over  the  paste.  The  whole  is  then  allowed  to  digest 
for  a  few  days,  when  it  is  pressed  and  filtered.  The  flavor  of 
raspberry  vinegar  is  improved  by  adding  10  drops  of  acetic 
ether  per  quart.  For  1  pound  of  pressed  residue  about  4  to  5 
quarts  of  strong  vinegar  are  used. 

Preparation  of  Acetic  Ether. — Among  the  numerous  combi- 
nations into  which. acetic  acid  enters  with  other  bodies,  acetic 
ether  is  of  special  value  for  the  vinegar  manufacturer,  it  being 
directly  used  in  the  manufacture  of  vinegar.  It  is  readily 
formed  on  alcohol  coming  in  contact  with  acetic  acid,  and  it 
would  seem  with  special  ease  when  the  latter  is  in  a  nascent 
state.  Hence  a  small  quantity  of  it  is  found  in  nearly  all  red 
wines  not  prepared  by  fermentation  in  closed  vats,  its  pres- 
ence being  due  to  the  formation  of  a  small  quantity  of  acetic 
acid  from  the  alcohol,  which  immediately  combines  with  the 
ethyl  oxide  or  ether. 

In  vinegar  containing  a  small  quantity  of  unchanged  alco- 
hol some  acetic  ether  formed  by  the  conversion  of  this  alcohol 
into  acetic  acid  is  always  present,  and  imparting  a  very  deli- 
cate and  agreeable  bouquet  to  the  vinegar,  it  is  recommended 
to  conduct  the  production  of  a  fine  article  so  that  it  contains 
a  small  quantity  of  it. 

It  is,  however,  not  absolutely  necessary  to  leave  a  small 
quantity  of  alcohol  in  the  vinegar,  as  either  acetic  ether  or  al- 
cohol can  be  directly  added  to  the  finished  product.  But  in 
both  cases  the  vinegar  has  to  be  stored  for  several  weeks ;  in 
the  first,  for  the  purpose  of  harmonizing  the  odors  of  acetic 
ether  and  of  acetic- acid,  and  in  the  latter,  for  the  formation  of 
acetic  ether. 


VINEGAR    SPECIALTIES.  185 

A  fluid  quite  rich  in  acetic  ether  and  very  suitable  for  im- 
parting bouquet  to  table  vinegar  can  in  a  very  simple  manner 
be  prepared  by  mixing  in  a  flask  one  volume  of  highly  concen- 
trated acetic  acid  with  95  or  96  per  cent,  alcohol,  and  after  clos- 
ing the  flask  air-tight,  allowing  the  fluid  to  stand  in  a  warm 
room  for  several  months.  The  resulting  fluid  is  used  as  an  ad- 
dition to  the  vinegar  whose  odor  is  to  be  improved.  Entirely 
pure  acetic  ether  is  best  prepared  in  the  following  manner  :  To 
9  parts  of  concentrated  sulphuric  acid  3.6  parts  of  commercial 
absolute  alcohol  are  added  by  means  of  a  funnel  tube  which 
reaches  to  the  bottom  of  the  vessel,  at  the  same  time  keeping 
the  liquid  well  stired.  After  standing  for  24  hours  this  mix- 
ture is  added  to  6  parts  of  sodium  acetate  which  has  previously 
been  fused  and  broken  in  small  fragments,  and  after  12  hours 
the  mixture  is  distilled.  Thus  6  parts  of  pure  acetic  ether  are 
obtained,  from  which,  by  rectifying  over  calcium  chloride,  all 
traces  of  water  are  removed. 

0  IT  O  ^ 
Pure  acetic  ether  or  ethyl  acetate  has  the  composition  p** 

and  represents  a  fluid  clear  as  water  with  an  agreeable  but 
stupefying  odor.  Its  specific  gravity  is  0.932  and  it  boils,  at 
165.2°  F.  On  account  of  its  volatility  it  has  to  be  kept  in 
well-stoppered  bottles,  best  in  a  cool  place. 

About  3J  to  7  ozs.  of  acetic  ether  suffice  for  the  improve- 
ment of  the  odor  of  100  quarts  of  vinegar. 


186  MANUFACTURE    OF    VINEGAR. 

CHAPTER  XVIII. 

MANUFACTURE    OF    WINE    VINEGAR. 

Since  wine  contains  between  6  and  14  per  cent,  of  alcohol, 
it  evidently  furnishes  an  excellent  material  for  vinegar  making. 
Both  white  and  red  wines  may  be  used  for  the  purpose,  but  as 
white  wine  vinegar  is  as  a  rule  preferred,  the  product  obtained 
from  red  wine  is  generally  not  salable  until  it  has  been  decol- 
orized, and  the  process  of  decolorizing  impairs  its  flavor  and 
aroma.  Vinegar  may  also  be  made  from  grapes  which  are 
unsuitable  for  drying,  shipping  or  wine  making,  and  this  may 
be  the  most  profitable  use,  in  some  cases,  to  which  even  the 
best  grapes  can  be  put.  If  grapes  are  used  they  must  of  course 
be  first  made  into  wine  by  the  usual  process.  According  to 
Bioletti*  one  ton  of  grapes  of  20°  Balling  should  on  the  aver- 
age yield  135  gallons  of  vinegar  of  9.8  per  cent,  acetic  acid. 
It  may  be  greater  or  less  than  this  according  as  the  grapes 
contain  more  or  less  sugar.  This  yield  may  be  diminished  by 
imperfect  crushing  and  pressing  of  the  grapes  whereby  more 
must  is  left  in  the  pomace.  Alcohol  may  be  lost  by  imperfect 
or  improper  fermentation  in  which  case  the  vinegar  will  be 
weaker.  The  greatest  difference  between  the  theoretical  and 
the  actual  yield  is  in  the  change  from  wine  into  vinegar. 
This  is  because  one  or  two  percent,  of  alcohol  remains  uncon- 
verted in  the  vinegar,  and  because  during  the  process  there  is 
a  considerable  loss  of  alcohol  and  acetic  acid  by  evaporation, 
and  by  reactions  within  the  liquid  which  produce  other  sub- 
stances at  the  expense  of  the  alcohol  and  acetic  acid.  If  the 
temperature  during  acetification  is  too  high,  or  if  the  acetic 
bacteria  are  allowed  to  act  too  long,  this  loss  may  be  much 
increased. 


*  Grape  Vinegar.     By  Frederic  T.  Bioletti.     University  of  California  Publica- 
tions.    Bulletin  No.  227,  1912. 


MANUFACTURE    OF    WINE    VINEGAR.  187 

By  allowing  the  crushed  grapes  to  ferment  on  the  skins 
before  pressing,  a  somewhat  larger  volume  of  wine  and  there- 
fore of  vinegar  may  be  obtained.  This  may  amount  to  150 
or  160  gallons  of  vinegar  from  a  ton  of  grapes.  The  vinegar, 
however,  will  be  darker  colored  and,  in  the  case  of  red  grapes, 
red.  This  color  can  be  removed,  but  the  decoloration  is  diffi- 
cult and  involves  some  loss  of  quality. 

Fermentation  for  twenty-four  hours  on  the  skins  will  much 
facilitate  the  extraction  of  the  juice  without,  except  in  the 
case  of  grapes  very  rich  in  coloring  matter,  reddening  the  juice 
very  much. 

The  question,  what  constitutes  the  superiority  of  wine  vine- 
gar over  the  ordinary  product  obtained  from  alcohol  is  not 
difficult  to  answer  for  those  who  have  an  accurate  knowledge 
of  the  constitution  of  wine.  Besides  the  ordinary  (ethyl)  alco- 
hol, wine  vinegar  contains  very  small  quantities  of  other 
alcohols,  for  instance,  amyl  alcohol,  which  in  the  same  man- 
ner as  ethyl  alcohol  is  converted  into  acetic  acid,  are  changed 
into  acids  possessing  a  peculiar  odor.  Moreover,  wine  very 
likely  contains  a  series  of  odoriferous  substances  which  pro- 
duce its  peculiar  aroma  termed  bouquet  or  flower,  the  cenan- 
thic  ether  found  in  every  wine  forming,  so  to  say,  the  keynote 
in  the  harmony  of  the  odoriferous  substances  constituting  the 
bouquet.  In  the  conversion  of  wine  into  vinegar  these  bou- 
quet substances  are  also  changed  in  such  a  manner  that 
bodies  distinguished  by  a  characteristic  odor  are  formed. 
Furthermore,  wine  contains  glycerin,  a  series  of  non-volatile 
organic  acids,  tartaric,  malic,  succinic  acids,  etc.,  and  finally 
the  so-called  extractive  substances.  What  changes  these  bodies 
undergo  is  not  accurately  known,  but  all  of  them  are  very 
likely  subject  to  certain  modifications  because  a  smaller  quan- 
tity of  extractive  substances  and  of  non-volatile  acids  is  found 
in  the  vinegar  than  in  the  original  wine.  The  following  table 
shows  the  composition  of  wine  and  of  the  vinegar  formed 
from  it : 


188  MANUFACTURE    OF    VINEGAR. 

Wine  contains—  Wine-vinegar  contains — 

Water,  Water, 

Ethyl  alcohol,  Ethyl  alcohol  (none  or  very  little) 

Other  alcohols,  Other  alcohols  (changed), 

Glycerin,  Glycerin  (less?) 

Acetic  acid,  (traces),  Acetic  acid  (much  newly  formed), 

Tartaric  acid,  Tartaric  acid  (less), 

Tartar,  Tartar  (less), 

Malic  acid,  Malic  acid  (less), 

Snccinic  acid,  Snccinic  acid  (less), 

Tannin,  Tannin  (changed), 

(Enanthic  ether,  (Enanthic  ether  (changed  and  unchanged), 

Bouquet  substances,  Bouquet  substances.     > 

Extractive  substances,  Extractive  substances  I  changed, 

Coloring  substances  Coloring  substances     J 

Acetic  ether  and  other  compound  \  newly 
ethers  /      formed. 

The  above  comparison  shows  the  thorough  modification 
wine  undergoes  in  being  converted  into  vinegar,  and  that  the 
resulting  product  must  have  a  bouquet  or  flower  having  a 
certain  connection  with  that  of  wine. 

Potable  wine  can  be  profitably  used  for  making  vinegar 
only  in  localities  where  in  consequence  of  a  very  abundant 
harvest  it  can  be  bought  at  a  very  low  price.  The  chief  sup- 
ply for  making  vinegar  is  derived  from  wines,  especially  from 
varieties  with  from  8  to  9  per  cent,  of  alcohol,  which  have 
deteriorated  on  account  of  incorrect  treatment  in  the  cellar,  and 
consequently  have  become  unsalable  as  a  beverage. 

The  term  "  sick  "  is  generally  applied  to  wines  in  which 
alterations  take  place  by  the  activity  of  a  certain  ferment  which, 
when  progressed  to  a  certain  degree,  renders  the  wine  unfit  for 
a  beverage.  "  Turning  sour  "  is,  for  instance,  a  sickness  fre- 
quently occurring  in  wines  poor  in  alcohol.  It  manifests  itself 
by  the  development  of  large  masses  of  a  certain  ferment  which 
quickly  destroys  the  tartaric  acid  contained  in  the  wine.  An- 
other sickness  chiefly,  occurring  in  red  wines  is  the  so-called 
"  turning  bitter,"  the  wine,  as  the  term  implies,  acquiring  in  a 
short  time  by  the  action  of  a  peculiar  ferment  such  a  disagree- 
able bitter  taste  as  to  render  it  absolutely  unfit  for  drinking. 


MANUFACTURE    OF    WINE    VINEGAR.  189 

Such  wine  cannot  be  used  even  for  vinegar,  the  latter  showing 
the  same  disagreeably  bitter  taste.  Wine  attacked  by  what  is 
called  "  lactic  acid  degeneration  "  can  be  used  for  the  manufac- 
ture of  vinegar,  but  yields  a  product  of  very  inferior  quality, 
because  on  the  wine  being  subjected  to  acetic  fermentation  the 
lactic  acid  contained  in  it  is  readily  converted  into  butyric  acid, 
which  possesses  a  disagreeable  rancid  odor  completely  killing 
the  pleasant  aroma  of  the  bouquet  substances.  There  only  re- 
mains as  a  material  actually  fit  for  the  preparation  of  wine- 
vinegar,  wine  attacked  by  "  acetic  degeneration,"  i.  e.,  wine  al- 
ready so  much  changed  by  the  vinegar  ferment  as  to  render 
it  unfit  for  a  beverage,  and,  further,  wine  which  though  not 
sick  is  unsound,  showing  a  taste  of  mold,  of  the  barrel,  etc. 

Wine  no  longer  young  and  not  overly  rich  in  alcohol  is 
especially  adapted  for  the  nutriment  of  the  vinegar  ferment. 
Such  wine  need  only  be  exposed  to  a  somewhat  higher  tem- 
perature in  order  to  induce  acetic  fermentation,  which  if  not 
disturbed  in  its  progress,  will  finally  convert  all  the  alcohol  in 
the  wine  to  acetic  acid. 

It  may  be  here  remarked  that  every  normal  wine  always  con- 
tains, besides  the  bodies  belonging  to  the  series  of  fatty  acids, 
acetic  acid,  though  only  about  a  few  ten-thousandths  of  its 
weight.  By  storing  the  wine,  the  acetic  acid  does  not  increase, 
but  becomes  rather  less,  it  being  consumed  in  the  formation  of 
compound  ethers.  Hence,  a  rapid  increase  of  the  acetic  acid 
is  an  indication  of  the  wine  being  attacked  by  acetic  degenera- 
tion, and  if  examined  with  the  microscope  the  ferment  charac* 
teristic  of  acetic  fermentation  will  be  found  upon  its  surface. 
Many  remedies  have  been  proposed  for  the  cure  of  acetic  de- 
generation, but  none  of  them  is  of  any  value  except  heating 
the  wine  to  about  140°  F.,  whereby  the  vinegar  ferment  is 
killed  and  the  further  progress  of  acetic  fermentation  checked. 
There  is,  however,  absolutely  no  remedy  for  the  removal  or 
neutralization  of  the  acetic  acid  already  present  in  the  wine. 
Heating  the  wine  can  only  be  recommended  when  the  evil  has 
been  in  existence  but  a  short  time  and  the  increase  of  acetic 


190  MANUFACTURE  OF  VINEGAR. 

acid  can  be  detected  only  by  a  very  sensitive  tongue.  Mixing 
wine  attacked  by  acetic  degeneration  with  sound  wine  in  order 
to  cover  the  acid  taste  is  especially  unadvisable,  since  nothing 
can  be  attained  by  it  except  a  short  delay  in  the  reappearance 
of  the  evil  and  the  transmission  of  the  infection  to  the  sound 
wine.  There  are  but  two  ways  in  which  wine  attacked  by 
acetic  degeneration  can  be  in  any  wise  profitably  utilized  :  By 
employing  it  for  the  preparation  of  cognac  or  converting  it  into 
wine-vinegar.  For  the  first  a  distilling  apparatus  is  required, 
and,  consequently,  cannot  be  effected  by  every  wine  grower, 
while  for  the  latter  nothing  is  necessary  but  a  few  vessels  read- 
ily procured. 

Young  wine  attacked  by  acetic  degeneration  is  also  fit  for 
nothing  else  than  the  preparation  of  vinegar.  On  account  of 
its  large  content  of  albuminous  substances  it  is,  however,  more 
suitable  for  the  nutriment  of  the  mold  ferment  than  for  that 
of  the  vinegar  ferment,  and  consequently  many  difficulties  oc- 
cur in  its  conversion  into  vinegar.  These  difficulties  can,  how- 
ever, be  largely  overcome  by  introducing  large  quantities  of 
air  into  such  wine  and  storing  for  some  time  in  barrels  filled 
up  to  the  bung,  or  heating  after  the  introduction  of  air  to  about 
140°  F.,  the  separation  of  the  albuminous  substances  being 
effected  by  either  means,  though  more  rapidly  by  the  latter. 
Before  further  working  the  wine  has  to  be  filtered  to  remove 
the  albuminous  substances  rendered  insoluble  by  the  treatment 
described,  since  their  presence  might  give  rise  to  injurious  com- 
plications. 

The  so-called  after  wine  obtained  from  grapes  once  pressed, 
by  a  process  introduced  by  Petiot,  is  a  very  suitable  material 
for  making  wine  vinegar,  since  after  fermentation  its  composi- 
tion as  regards  alcohol  and  extractive  substances  is  very  advan- 
tageous. For  successfully  carrying  out  the  process  it  is  abso- 
lutely necessary  to  work  the  marc  fresh  from  the  press. 

According  to  Paul  Hassack  *  there  are  used  for  the  purpose, 

*  Gahrungs-Essig,  1904. 


MANUFACTURE    OF    WINE    VINEGAR. 


191 


FIG.  45. 


400  Ibs.  fresh  marc,*  150  Ibs.  glucose  and   1000  quarts  of 
water. 

The  glucose  is  dissolved  in  about  400  quarts  of  hot  water, 
and  after  making  the  whole  up  to  1000  quarts  by  the  addition 
of  600  quarts  of  cold  water,  the  solu- 
tion is  thoroughly  stirred. 

In  the  meanwhile  400  Ibs.  of  fresh 
marc  are  brought  into  a  fermenta- 
tion-vat Fig.  45,  and  the  sugar  solu- 
tion at  a  temperature  of  72°  to  75° 
F.  is  poured  over  them.  The  marc 
should  be  broken  up,  and  not 
brought  into  the  vat  in  large  lumps. 
Fermentation  as  a  rule  commences 
after  six  hours  and  as  by  it  the  marc 
is  forced  to  the  surface,  the  vat,  as 
will  be  seen  from  the  illustration,  is 
furnished  with  a  perforated  head  B, 
by  which  the  marc  is  kept  below  the  level  of  the  liquid. 
Fermentation  is  effected  under  exclusion  of  the  air,  a  hydraulic 
ventilating  bung  g  being  used,  which  permits  the  escape  of 
carbonic  acid  but  does  not  allow  air  to  enter.  Fermentation 
is  best  carried  on  at  a  temperature  of  68°  to  75°  F.,  and  the 
fermenting  liquid  is  allowed  to  remain  in  the  vat  till  but  a 
very  weak  current  of  carbonic  acid  escapes  through  the  venti- 
lating bung  (about  6  to  8  days).  The  young  wine  is  then 
as  quickly  as  possible  racked  off  into  barrels  for  the  second  or 
after-fermentation.  In  filling  the  barrels  it  is  advisable  to 
pass  the  wine  through  a  medium  fine  hair- sieve.  The  wine 
should  not  come  in  contact  with  the  air  any  more  than  can 
possibly  be  avoided  to  prevent  it  from  acquiring  a  darker 
color.  The  marc  is  taken  from  the  fermentation-vat  and 
pressed. 

*  An  addition  of  1  Ib.  or  more  of  crushed  quinces  per  100  Ibs.  of  marc  imparts 
to  the  wine  and  indirectly  to  the  vinegar  a  very  agreeable  aroma,  and  the  large 
content  of  tannin  effects  a  more  rapid  clearing  of  the  wine. 


192  MANUFACTURE    OF    VINEGAR. 

An  addition  of  tartaric  acid  to  wine  prepared  by  the  above- 
described  process  is  seldom  required,  and  in  any  case  a  solu- 
tion of  crystallized  acid  per  100  quarts  of  the  wine  when 
racked  off  for  the  second  fermentation  will  be  sufficient.  The 
treatment  of  the  young  wine  in  the  cellar  is  the  same  as  that 
of  original  wine.  The  barrels  should  be  kept  full  up  to  the 
bung.  During  the  first  two  weeks  of  the  second  fermentation 
it  is  of  advantage  to  have  a  ventilating  bung  in  each  barrel. 
By  taking  into  consideration  the  sugar  solution  that  has  been 
added  to  the  marc  and  the  sugar  contained  in  the  latter  itself, 
the  wine,  when  fermentation  is  finished,  will  contain  about  7 
to  8  per  cent,  alcohol,  5  to  10  per  cent,  acid,  0.5  per  cent, 
sugar  and  l.G  to  2.3  per  cent,  extract  free  from  sugar,  and 
would  yield  vinegar  with  5.6  to  6.  5  per  cent,  acetic  acid. 

The  wine  thus  obtained  when  carefully  made  is  dark  yellow, 
has  an  agreeably  pure  taste,  and  its  odor  is  aromatic  and  rich 
in  bouquet.  When  made  with  the  exclusion  of  air,  it  is 
durable,  easily  managed,  and  clarifies  readily.  After  racking 
off  several  times  into  clean,  slightly  sulphured  barrels,  it  is 
clarified  by  means  of  isinglass  solution  or  filtering  through  a 
linen  or  paper  filter.  For  fining  with  isinglass  J  to  J  oz.  of 
isinglass  is  sufficient  for  each  100  gallons  of  wine.  Pound 
the  isinglass,  cut  it  into  small  pieces  and  soak  it  for  12  to  24 
hours  in  fresh  water.  When  taken  from  the  water,  squeeze 
it  thoroughly  and  bring  it  into  a  vessel  together  with  1  gallon 
of  water  in  which  f  oz.  of  tartaric  acid  has  previously  been 
dissolved.  The  isinglass  swells  up  and  is  converted  into  a 
thin  jelly-like  mass.  Dilute  this  solution  with  40  gallons  of 
wine,  add  it  to  the  wine  to  be  fined  and  stir  thoroughly. 
Very  young  turbid  after-wine  is  not  fit  for  making  wine 
vinegar.  After-wine  for  vinegar  making  should  be  perfectly 
bright,  and  at  least  4  to  6  months  old. 

Before  entering  upon  a  description  of  the  various  methods 
of  making  wine  vinegar  it  may  be  mentioned  that  a  product 
of  actually  fine  quality  can  only  be  obtained  by  a  slow  pro- 
cess of  acetification,  wine  treated  by  the  quick  process  yielding 
a  product  very  poor  in  bouquet. 


MANUFACTURE    OP    WINE    VINEGAR.  193 

The  oldest  method  for  making  wine  vinegar  is  that  to  which 
the  term  "  boiling  of  wine  vinegar"  (Weinessig  Siederei)  has 
been  applied.  A  barrel  was  filled  f  full  with  wine  to  be  con- 
verted into  vinegar ;  a  portion  of  the  fluid  was  then  heated  to 
boiling  and  poured  back  into  the  barrel.  Upon  the  wine 
thus  heated  to  about  8(3°  F.,  the  development  of  the  vinegar 
ferment  commenced,  and  in  the  course  of  a  few  months  the 
greater  portion  of  the  alcohol  was  converted  into  acetic  acid. 
The  greater  portion  of  the  contents  of  the  barrel  was  then 
drawn  off  as  "  ripe  wine  vinegar,"  the  barrel  again  filled  f 
full  with  wine,  and  a  portion  of  this  heated.  The  operation 
was  continued  in  this  manner  until  so  much  slimy  sediment 
had  accumulated  in  the  barrel  as  to  render  it  necessary  to 
entirely  empty  and  clean  it.  This  crude  process,  which,  as 
mentioned,  was  known  in  Germany  as  "  vinegar  boiling,"  was 
similar  to  the  method  formerly  in  general  use  in  France,  and 
which,  being  still  partially  practised  there  in  some  large  wine- 
vinegar  factories,  for  instance  in  Orleans,  may  be  designated 
as  the 

Orleans  or  old  French  Process  of  Making  Wine  Vinegar.  The 
casks,  called  mothers,  which  are  employed,  hold  not  more 
than  22  gallons,  each  cask  being  filled  |  full.  Immediately 
above  the  level  of  the  fluid  a  hole  is  bored  in  the  surface  of 
the  front  end  of  each  cask,  this  hole  as  well  as  the  bung-hole 
remaining  open  ;  a  stop-cock  for  the  discharge  of  the  fluid  is 
placed  in  the  lower  part  of  the  cask.  The  casks  are  placed  in 
rows  in  the  open  air,  eight,  ten.  fifteen,  or  twenty  such  rows 
constituting  what  is  termed  a  vinegar  field.  This  so-called 
fielding,  which  is  carried  on  from  spring  to  fall,  may  be  suitable 
for  the  southern  part  of  France,  but  cannot  be  recommended 
for  more  northern  regions,  as  the  temperature  may  fall  very  low 
during  the  night  and  rise  very  high  during  the  day.  Exper- 
ience has  shown  that  the  propagation  and  efficacy  of  the  fer- 
ments are  very  much  injured  by  great  variations  of  tempera- 
ture, and  consequently  it  is  decidedly  preferable  to  keep  the 
casks  in  a  room  the  temperature  of  which  can  be  maintained 
13 


194  MANUFACTURE    OP    VINEGAR. 

at,  at  least  68°  F.  The  wine  remains  in  these  casks  until  it  is 
converted  into  vinegar.  The  latter  is  then  drawn  off  by  means 
of  the  above-mentioned  stop-cock  and  the  casks  are  again  filled 
with  wine,  etc.  The  hole  in  the  front  end  of  the  cask  and  the 
bung-hole  permit  the  free  access  of  air  to  the  surface  of  the 
wine.  In  other  French  factories  the  work  is  carried  on  accord- 
ing to  a  method  somewhat  different  from  the  one  just  described. 
Casks  having  a  capacity  of  up  to  100  gallons  are  used,  each 
cask  having  in  the  surface  of  the  front  end  a  square  aperture, 
which  serves  to  charge  the  casks  with  wine  as  well  as  for  the 
entrance  of  air.  The  casks  are  placed  in  three  rows  one  above 
another  in  a  room  which  can  be  heated.  In  the  beginning  of 
the  operation  a  certain  quantity  of  strong  vinegar  is  brought 
into  the  casks ;  about  one-fourth  of  its  volume  of  wine  is  then 
added,  and  at  intervals  of  eight  days  about  10  quarts  more. 
When  the  cask  is  nearly  filled  up  to  the  above-mentioned  aper- 
ture, the  regular  process  of  drawing  off  vinegar  and  filling  up 
again  with  wine  is  commenced.  If,  for  instance,  10  quarts  of 
finished  vinegar  are  drawn  off,  the  same  quantity  of  wine  is  re- 
placed in  the  cask,  and  suppose  that,  according  to  the  manner 
of  working,  7,  8,  or  10  days  are  required  for  the  conversion  of 
this  quantity  into  vinegar,  10  quarts  of  vinegar  are  again  drawn 
off  after  the  expiration  of  that  time,  this  being  continued  until 
a  disturbance  occurs. 

In  the  course  of  time  large  masses  of  slimy  matter  consist- 
ing of  albuminous  substances,  vinegar  ferment  vegetating 
below  the  surface  (the  so-called  mother  of  vinegar),  decayed 
vinegar  ferment,  etc.,  form  a  deposit  in  the  cask,  and  finally 
accumulate  to  such  an  extent  as  to  occupy  half  the  volume  of 
the  cask,  so  that  the  latter  has  to  be  emptied  and  thoroughly 
cleansed.  Sometimes  the  operation  has  to  be  interrupted 
much  sooner  on  account  of  the  contents  of  the  cask  acquiring 
a  disagreeable,  putrid  odor.  The  appearance  of  putrefaction 
is  generally  due  to  vinegar  eels  settling  in  the  interior  of  the 
cask — as  a  rule,  immediately  above  the  level  of  the  fluid — 
and  developing  to  such  an  extent  that  they  form  a  slimy  coat- 


MANUFACTURE    OF    WINE    VINEGAR.  195 

ing  on  the  cask  and  upon  the  fluid  and  suppress  the  develop- 
ment of  the  vinegar  ferment.  These  animalcules  are  de- 
stroyed by  being  deprived  of  air,  and,  hence,  when  the  vinegar 
ferment  is  brought  to  vigorous  development  it  withdraws  so 
much  of  the  oxygen  from  the  air  in  the  cask  that  many  of 
them  die  and  their  bodies  sink  to  the  bottom,  where  they 
sooner  or  later  putrefy.  If  this  putrefying  process  takes  place 
before  a  cleansing  of  the  casks  is  considered  necessary,  it  pro- 
gresses to  such  an  extent  that  the  entire  contents  of  the  cask 
are  converted  into  a  stinking  mass  which  has  to  be  removed 
as  quickly  as  possible.  The  casks  in  which  such  disturbances 
takes  place  must  of  course  be  carefully  cleansed  by  sulphuring 
and  washing  with  boiling  water  before  they  are  again  used. 

The  above-described  method  of  making  vinegar  is  full  of 
defects.  The  presence  of  vinegar  in  a  fluid  which  itself  is  to 
be  converted  into  vinegar  promotes,  to  be  sure,  the  formation 
of  acetic  acid,  but  is  not  absolutely  necessary,  as  has  been  fre- 
quently asserted,  for  the  induction  of  the  process.  If  such 
were  the  case,  it  would  evidently  be  impossible  for  an  alcoholic 
liquid,  such  as  beer  or  wine  to  pass  on  its  own  account  into 
acetic  fermentation.  The  acetification  of  the  casks  with  boil- 
ing vinegar  is  irrational,  because  by  heating  the  vinegar  and 
pouring  it  boiling  hot  into  the  casks,  not  only  the  vinegar  fer- 
ment contained  in  it,  but  also  that  present  in  the  cask  or  wine, 
is,  if  not  absolutely  killed,  at  least  weakened  to  such  an  extent 
as  to  be  incapable  of  converting  alcohol  into  acetic  acid. 
That  acetic  fermentation  nevertheless  takes  place  is  very  likely 
due  to  the  following  causes. 

The  hot  fluid  in  the  cask  gradually  cools  off  and  is  finally 
reduced  to  a  degree  of  temperature  most  favorable  to  the  de- 
velopment of  the  vinegar  ferment ;  in  the  same  proportion  as 
cooling-off  takes  place  the  air  contracts  in  the  cask  and  air 
enters  from  the  outside.  The  latter,  however,  carries  with  it 
germs  of  vinegar  ferment  which  rapidly  develop  upon  the 
fluid  when  reduced  to  the  proper  temperature  and  cause  its 
acetification.  The  air  penetrating  into  the  cask  may,  how- 


196  MANUFACTURE    OF    VINEGAR. 

ever,  accidentally  contain  no  vinegar  ferment,  or  that  con- 
tained in  it  may  not  reach  the  wine  ;  in  such  case  the  wine 
may  for  weeks  remain  in  the  cask  without  any  perceptible 
acetification  taking  place  until  the  latter  finally  appears  by  an 
accidental  development  of  the  vinegar  ferment.  This  uncer- 
tainty 'can,  however,  be  readily  avoided  by  the  direct  cul- 
ture by  the  vinegar  ferment  upon  the.  wine  to  be  acetified. 
Milk,  as  is  well  known,  turns  sour  on  exposure  to  the  air  by 
the  milk  sugar  being  converted  into  lactic  acid  by  the  action 
of  a  ferment  frequently  occurring  in  the  air,  this  souring 
taking  place  in  several  hours  or  several  days  according  to  the 
temperature 'to  which  the  milk  is  exposed.  It  is  further  a 
well-known  fact  that  the  addition  of  a  few  drops  of  sour  to 
sweet  milk  suffices  to  immediately  induce  the  formation  of 
lactic  acid  in  the  latter;  the  ferment  of  lactic  acid  fermenta- 
tion being  in  the  true  sense  of  the  word  sowed  upon  the  milk. 
The  ferment  develops  very  rapidly,  converts  the  sugar  into 
lactic  acid,  and  in  a  short  time  turns  the  entire  quantity  of 
milk  sour. 

Exactly  the  same  course  may  be  pursued  as  regards  the 
vinegar  ferment,  it  being  only  necessary  to  mix  the  wine  with 
a  fluid  containing  living  vinegar  ferment  and  place  it  in  a 
sufficiently  warm  room  in  order  to  immediately  start  the  pro- 
cess of  the  formation  of  acetic  acid.  In  this  case  the  vinegar 
ferment  is  sowed  upon  the  wine,  or  in  other  words,  the  wine 
is  impregnated  with  vinegar  ferment  and  intentionally  made 
"  sick."  This  method  of  transmitting  ferment  to  the  fluid  to 
be  fermented  has  for  a  long  time  been  in  use  in  the  prepara- 
tion of  beer  and  of  alcohol.  In  the  brewery  the  wort,  and  in 
the  distillery,  the  mash,  is  brought  into  fermentation  by  "  set- 
ting" it  with  yeast,  i.  e.,  alcoholic  ferment  is  intentionally 
added.  The  "  setting  of  wine"  with  vinegar  ferment  is  the 
only  correct  method  for  the  preparation  of  vinegar  from  wine. 

Pasteur's,  or  Modern  French  Method  of  Preparing  Wine  Vine- 
gar. Pasteur,  as  previously  mentioned,  made  exhaustive  in- 
vestigations regarding  the  conditions  essential  to  the  life  of 


MANUFACTURE    OF    WINE    VINEGAR. 


197 


the  vinegar  ferment,  and  found  that  it  thrives  especially  well 
upon  a  liquid  which  in  addition  to  water,  alcohol  and  vinegar, 
contains  a  trace  of  phosphates.  The  latter  is  absolutely  neces- 
sary for  the  propagation  of  the  ferment;  if  wanting,  the  fer- 
ment cannot  attain  vigorous  development.  Pasteur  recom- 
mends a  liquid  consisting  of  boiled  water  100  per  cent.,  pure 
alcohol  2,  crystallized  glacial  acetic  acid  1,  phosphate  *-0.  As 
an  inorganic  combination  that  contains  all  the  substances  re- 
quired for  the  nutriment  and  development  of  the  vinegar  fer- 
ment, Pasteur  gives  the  following  mixture  of  phosphate  :  Po- 

FIG.  46. 


tassiurn  phosphate  1   part  by  weight,  calcium   phosphate  1, 
ammonium  phosphate  2,  magnesium  phosphate  1. 

The  liquid  prepared  according  to  the  above  directions  is 
exposed  to  the  action  of  the  air  at  a  temperature  of  68°  to  77° 
F.  In  a  short  time  the  surface  of  the  liquid  becomes  covered 
with  the  vinegar  ferment  and  by  the  agency  of  the  latter  the 
alcohol  present  is  converted  into  acetic  acid.  In  the  mean- 
while a  corresponding  quantity  of  wine  has  been  sterilized  by 


198  MANUFACTURE  OF  VINEGAR. 

heating  it  to  between  158°  to  176°  F.  This  process  is  called 
"Pasteurization"  and  may  be  effected  in  various  ways,  an 
apparatus  for  that  purpose  being  shown  in  Fig.  46.*  Upon 
the  furnace  C  sits  a  vessel  F  filled  with  boiling  water.  In 
this  vessel  lies  a  coil  of  pipe  tinned,  or  better,  silvered  inside. 
A  similar  coil  also  tinned  inside  lies  in  the  preparatory  heater 
and  cooler  B.  The  wine  to  be  heated  is  contained  in  the  vat 
A.  It  passes  through  g,  /,  o,  d,  to  B,  and  when  the  latter  is 
full,  passes  through  e  into  the  coil  in  F,  where  it  is  heated,  the 
temperature  of  the  liquid  being  indicated  by  the  thermometer 
h.  From  the  coil  in  F,  the  pasteurized  liquid  is  cooled  by 
passing  through  a  through  the  coil  in  B,  heating  at  the  same 
time  the  wine  in  B,  and  finally  runs  off  at  d.  By  regulating 
the  cocks  6,  e,  and  a,  the  quantity  of  wine  passing  through  the 
apparatus  can  be  readily  controlled  so  that  the  thermometer 
h  constantly  indicates  a  temperature  between  131°  and  140°  F. 

Various  methods  based  on  the  researches  of  Pasteur  have 
been  devised,  but  before  entering  upon  a  description  of  the 
process,  it  will  be  necessary  to  discuss  a  few  undesirable  phe- 
nomena which  may  appear  in  the  conversion  of  wine  into 
vinegar.  A  thick  white  skin  having  the  appearance  of  a  ruffle 
may  frequently  form  upon  the  surface  of  the  wine  to  be  aceti- 
fied, the  wine  in  this  case  becoming  constantly  poorer  in  alco- 
hol, but  does  not  show  acidity.  Sometimes  the  previously 
steady  increase  in  the  content  of  acid  in  the  wine  suddenly 
ceases  and  a  very  rapid  decrease  in  the  content  of  acid  takes 
place,  the  development  of  the  white  skin  upon  the  surface 
being  also  in  this  case  observed. 

The  formation  of  this  white  coating  upon  the  surface  is  due 
to  the  development  of  mold  ferment  which  in  a  short  time 
propagates  to  such  an  extent  as  to  form  a  thick  membranous 
layer,  the  folds  being  formed  by  the  superposition  of  the  cells. 
The  mold  ferment  has  the  property  of  converting  alcohol  as 
well  as  acetic  acid  into  carbonic  acid  and  water,  and  conse- 

*  Gahrungs-Essig  by  Paul  Hassack. 


MANUFACTURE    OP    WINE    VINEGAR.  199 

quently  if  it  settles  upon  the  wine  the  latter  becomes  poorer 
in  alcohol,  and  if  upon  wine  containing  already  a  certain 
quantity  of  acetic  acid  the  latter  is  also  decomposed.  The 
mold  ferment  requires,  however,  considerable  quantities  of 
nitrogenous  combinations  for  its  vigorous  development,  and 
therefore,  readily  settles  upon  young  wine  which  contains  a 
large  quantity  of  albuminous  bodies  in  solution.  This  fact 
explains  the  reason  why  young  wine  is  seldom  attacked  by 
acetic  degeneration,  but  it  readily  becomes  moldy,  and,  con- 
sequently cannot  be  recommended  as  vinegar  material  except 
the  albuminous  substances  be  first  separated  by  heating  the 
wine  to  140°  F.,  which  is  best  effected  by  means  of  the  appa- 
ratus shown  in  Fig.  42. 

Another  serious  annoyance  in  making  wine-vinegar  is  the 
appearance  of  vinegar  eels,  which,  if  not  checked  in  time,  may 
lead  to  the  interruption  of  the  entire  process.  These  animal- 
cules are  seldom  found  in  factories  working  with  pump  or  well 
water,  but  frequently  in  those  using  river  water,  and  conse- 
quently their  introduction  is  likely  due  to  such  water.  In 
case  of  their  appearance  in  large  masses  it  is  best  to  interrupt 
the  process  in  time  in  order  to  prevent  the  previously  men- 
tioned phenomena  of  putrefaction.  The  fluid  containing  the 
vinegar-eels  should  be  drawn  off  into  a  thoroughly  sulphured 
barrel.  The  sulphurous  acid  kills  the  vinegar  eels  as  well  as 
the  vinegar  ferment,  and  the  filtered  fluid,  after  standing  a 
few  weeks,  whereby  the  sulphurous  acid  is  converted  into  sul- 
phuric acid,  can  again  be  used  as  alcoholic  liquid.  The  ves- 
sels in  which  the  vinegar  eels  have  settled  must  also  be 
thoroughly  sulphured  and  then  repeatedly  washed  with  water 
before  being  re- used  for  making  vinegar. 

Throughout  the  entire  factory  the  greatest  cleanliness  should 
prevail ;  in  fact  one  cannot  be  too  scrupulous  in  this  respect, 
as  otherwise  by-fermentations  readily  take  place,  and  another 
plague,  the  vinegar  lice,  or  more  correctly  vinegar  mites  (see 
p.  140)  may  appear.  Should  either  of  these  drawbacks  happen, 
the  workroom,  fluids,  and  vessels  should  be  thoroughly  disin- 
fected by  means  of  sulphurous  acid. 


200  MANUFACTURE    OF    VINEGAR. 

As  previously  mentioned  the  Orleans  method  of  making 
wine-vinegar  cannot  be  recommended,  it  being  slow  and  la- 
borious, and  besides  there  is  considerable  loss  of  material  by 
evaporation  and  by  the  formation  of  large  masses  of  gelatinous 
"  mother  of  vinegar,"  which  depreciates  the  quality  and  ne- 
cessitates expensive  cleaning  of  the  casks. 

Claudon's  Method  of  Making  Wine  Vinegar.  This  is  one  of 
the  methods  based  on  the  researches  of  Pasteur.  The  appara- 
tus used,  Fig.  47  is  described  by  Frederic  T.  Bioletti  *  as 
follows:  "  It  consists  essentially  of  a  wide,  shallow,  covered, 
rectangular  vat,  furnished  with  numerous  openings  near  the 
top,  a  by  which  the  entrance  of  air  can  be  facilitated  and 

Fig  47. 


Da     a       a      Da    a       a     .a      Da 


regulated.  This  vat  is  filled  to  near  the  bottom  of  the  air 
vents  with  a  mixture  of  4  parts  of  good  new  wine  and  G  parts 
of  wine  which  has  been  pasteurized  at  140°  F.,  and  when  ne- 
cessary filtered.  On  top  of  this  liquid  is  floated  a  light  wooden 
grating  /,  which  helps  to  support  the  bacterial  film  and  pre- 
vents its  breaking  and  submerging  during  the  various  opera- 
tions. When  filled,  the  process  is  started  by  placing  a  small 
quantity  of  a  good  bacterial  film  on  top  of  the  liquid  which 
soon  becomes  completely  covered  when  the  proper  conditions 
of  temperature  and  aeration  are  maintained. 

"Each  acetifying  vat  is  connected  with  a  small  measuring 
vat  R  from  which  the  proper  amount  of  liquid  is  taken  every 

*  "  Grape  Vinegar."     University  of  California  Publications  College  of  Agricul- 
ture, Agricultural  Experiment  Station.     Bulletin  No.  227,  1912. 


MANUFACTURE    OF    WINE    VINEGAR.  201 

day  after  a  corresponding  amount  of  vinegar  has  been  removed. 
These  two  vats  constitute  a  unit,  several  of  which,  usually  six, 
are  united  in  a  battery.  A  factory  includes  several  of  these 
batteries. 

"  The  batteries  are  fed  from  a  large  vat  or  reservoir,  where 
the  mixture  of  wine  and  vinegar  is  prepared  and  stored.  The 
vinegar  drawn  from  the  batteries  runs  directly  to  filters,  from 
there  to  a  pasteurizer,  and  thence  to  the  storage  casks.  The 
output  of  these  batteries  is  from  two  to  five  times  as  great 
per  square  yard  of  acetifying  surface  as  that  of  the  old  methods; 
the  cost  of  operation  is  considerably  less,  the  loss  by  evapora- 
tion much  reduced,  and  the  quality  equal  and  much  more 
under  the  Control  of  the  manufacturer." 

Rersch's  MetJtod  of  Making  Wine-  Vinegar.  The  essential  part 
of  the  entire  process  is  the  impregnation  of  the  wine  in  suitable 
vessels  with  pure  vinegar  ferment  under  conditions  suitable 
for  the  rapid  propagation  of  the  ferment.  The  vessels  are  so 
arranged  that  the  finished  vinegar  can  be  removed  and  replaced 
by  wine  to  be  acetified  without  disturbing  the  ferment,  one 
being  thus  enabled  to  uninterruptedly  continue  the  process  of 
the  formation  of  vinegar  for  a  long  time,  and  producing 
vinegar  unsurpassed  by  any  other  product  as  regards  delicacy 
of  taste  and  odor.  According  to  the  above  statement,  the 
operation  includes  the  culture  of  the  vinegar  ferment  on  a 
small  scale  and  on  a  large  scale,  the  former  for  the  production 
of  pure  ferment  and  the  latter  for  obtaining  wine-vinegar. 

The  culture  of  pure  vinegar  ferment  on  a  small  scale  is  best 
effected  by  heating  wine  in  a  porcelain  or  glass  dish  to  between 
140°  and  150°  F.,  then  mixing  it  with  an  equal  volume  of  vine- 
gar and  pouring  the  resulting  fluid  into  shallow  porcelain  plates, 
which  are  placed  in  a  warm  room.  In  a  short  time,  generally 
in  24  to  30  hours,  the  veil-like  layer  of  vinegar  ferment  pre- 
viously described  is  observed  upon  the  surface  of  the  fluid.  If, 
besides  the  dull  spots  which  are  characteristic  of  pure  vinegar 
ferment,  spots  of  pure  white  color  are  formed,  it  is  an  indica- 
tion of  the  development  of  mold  ferment.  The  contents  of 


202  MANUFACTURE    OF    VINEGAR. 

the  plates  showing  this  phenomenon  have  to  be  boiled  and 
then  again  exposed  to  the  air. 

The  wine  to  be  acetified  is  in  large,  shallow  vats,  and  is 
brought  to  fermentation  by  carefully  submerging  in  it  one  of 
the  above-mentioned  plates  containing  pure  vinegar  ferment, 
so  that  the  latter  is  distributed  upon  the  surface ;  the  plate  is 
then  withdrawn.  The  ferment  propagates  very  rapidly,  so 
that,  in  24  hours,  the  surface  of  the  wine  in  the  vat  is  entirely 
covered  with  a  thin  veil  of  it.  By  keeping  the  temperature 
of  the  room  in  which  the  vats  are  placed  at  about  68°  F.,  the 
acetification  of  the  wine  proceeds  rapidly,  tests  repeated  at  in- 
tervals of  24  hours  showing  a  constant  increase  in  the  content 
of  acid,  until  in  about  8  days  all  the  wine  is  converted  into 
vinegar  when  it  is  drawn  off.  To  avoid  the  necessity  of  es- 
pecially impregnating  the  next  quantity  of  wine  the  finished 
vinegar  is  not  entirely  drawn  off,  a  small  quantity,  (about  f  to 
an  inch  deep),  upon  the  surface  of  which  the  vinegar  ferment 
floats,  being  allowed  to  remain  in  the  vat.  By  now  introduc- 
ing'a  fresh  lot  of  wine  the  vinegar  ferment  propagates  upon 
it  and  after  some  time  converts  it  into  vinegar. 

With  sufficient  care  the  process  of  the  formation  of  vinegar 
could  thus  be  uninterruptedly  carried  on  for  any  length  of  time 
by  transferring  the  vinegar  ferment  from  the  finished  vinegar 
to  the  wine,  if  a  cleansing  of  the  vat  were  not  from  time  to 
time  required,  on  account  of  the  accumulation  on  the  bottom 
of  the  vessel  of  decayed  vinegar  ferment  and  flakes  of  albumen 
which  have  become  insoluble.  When  the  vat  is  to  be  cleansed 
the  last  batch  of  vinegar  is  to  be  drawn  off  as  long  as  it  runs  off 
clear,  and  the  turbid  remainder  in  the  bottom  of  the  vat  is 
collected  in  a  special  cask,  where  it  is  allowed  to  clarify.  The 
vat  is  then  thoroughly  cleansed  with  water,  and  after  filling 
it  again  with  wine,  the  latter  is  mixed  with  pure  vinegar 
ferment  in  the  manner  already  described. 

If,  as  may  happen  in  very  rare  cases,  mold  ferment  in  the 
form  of  the  above-mentioned  white  spots  appears  upon  the 
surface  besides  vinegar  ferment,  the  vat  must  at  once  be 


MANUFACTURE    OF    WINE    VINEGAR.  203 

emptied.  The  process  should  also  be  interrupted  in  case  of  the 
development  of  the  so-called  mother  of  vinegar.  The  latter 
appears  generally  in  the  form  of  a  soft  gelatinous  mass  sub- 
merged in  the  fluid,  and  consists  of  vinegar  ferment,  which, 
however,  on  account  of  not  being  in  direct  contact  with  the 
air,  does  not  produce  acetic  acid.  The  fluid  to  be  acetified 
can  be  readily  separated  from  the  mother  of  vinegar  by  filter- 
ing through  a  close  cloth,  the  mother  of  vinegar  remaining 
upon  the  latter  and  finally  drying  to  a  whitish  mass  resemb- 
ling very  thin  tissue  paper. 

From.the  above  description  it  will  be  seen  that  the  rational 
preparation  of  wine-vinegar  is  a  very  simple  matter  ;  but  there 
are  some  difficulties  which  can,  however,  be  entirely  prevented 
or  readily  overcome.  The  vinegar  ferment  is  very  sensitive 
towards  sudden  changes  in  the  composition  of  the  fluid  upon 
which  it  lives,  as  well  as  towards  rapid  changes  in  the  tem- 
perature. The  sudden  change  in  the  composition  of  the  fluid 
is  prevented  by  not  drawing  off  all  the  finished  vinegar,  but 
allowing  a  small  portion  of  it  to  remain  in  the  vat.  The 
fresh  supply  of  wine  entering  from  below  then  lifts  up  the  re- 
mainder of  vinegar,  together  with  the  ferment  floating  upon 
it,  and  the  mixture  of  both  fluids  is  effected  so  gradually  that 
the  change  in  the  composition  of  the  nourishing  fluid  proceeds 
very  slowly.  A  sudden  change  in  the  temperature  of  the  work- 
room can,  of  course,  be  readily  prevented  by  proper  heating. 

Ripe  wines  with  not  much  above  6  per  cent,  of  alcohol  are 
the  best  to  use,  as  they  yield  vinegar  with  about  5J  per  cent, 
of  acetic  acid.  Stronger  wines  with  a  content  of  alcohol  up  to 
10  per  cent.,  are,  however,  best  reduced  to  about  6  per  cent., 
either  by  water  or  ordinary  vinegar.  The  strength  of  the 
latter  must  be  so  chosen  that  the  wine-vinegar  prepared  from 
a  mixture  of  wine  and  vinegar  contains  5J  to  6  per  cent,  of 
acetic  acid.  The  proportions  in  which  vinegar  and  wine  are 
to  be  mixed  for  this  purpose  are  found  by  a  simple  calculation 
after  an  accurate  determination  of  the  content  of  alcohol  in 
the  wine  and  that  of  acetic  acid  in  the  vinegar. 


204  MANUFACTURE  OF  VINEGAR. 

The  workroom  should  be  so  situated  as  to  be  protected 
against  sudden  changes  in  the  temperature  and  provided  with 
a  furnace  or  self- regulating  stove.  The  vessels  for  the  forma- 
tion of  vinegar  are  placed  upon  suitable  supports,  and  tables 
for  holding  the  plates  for  the  culture  of  the  vinegar  ferment 
should  be  provided.  If  the  size  of  the  room  permit,  it  is  ad- 
visable to  store  in  it  a  few  barrels  of  the  material  to  be  worked, 
the  fluid  thereby  gradually  acquiring  the  proper  temperature. 

For  the  formation  of  the  vinegar  very  shallow  vats,  best  with 
a  diameter  of  3 J  to  5  feet  and  a  depth  of  9  to  14  inches,  are 
used. 

The  iron  hoops  are  protected  from  the  action  of  the  acid 
vapors  by  a  coat  of  asphalt  lacquer.  The  vats  are  placed  in 

FIG.  48. 


H 


the  position  they  are  to  occupy  in  the  workroom  and  filled 
with  water  up  to  about  If  to  3}  inches  from  the  top,  the 
height  of  the  level  of  the  fluid  being  marked  on  the  inside  wall. 
At  distances  of  3  j  inches  apart,  and  5}  in  large  vats,  holes, 
I,  Fig.  48  of  0.39  inch  diameter  are  then  bored  in  the  wall  of 
the  vat.  One  hole,  however,  is  bored  in  a  place  about  0.39 
inch  deeper  than  I,  and  in  this  hole  is  fitted  a  glass  tube,  g, 
bent  at  a  right  angle,  under  which  is  placed  an  ordinary  tumb- 
ler. In  the  bottom  of  the  vat  is  a  tap-hole,  Z,  closed  by  a 
stopper. 

If  the  vat  be  filled  during  the  operation  with  wine,  the  latter 
can  only  rise  until  it  begins  to  run  off  at  g.  The  level  of  the 
fluid  being  but  little  below  the  holes  I,  an  uniterrupted  change 


MANUFACTURE    OF    WINE    VINEGAR.  205 

in  the  layer  of  air  above  the  fluid  takes  place.  A  wooden 
spigot,  //,  is  fitted  in  the  vat  about  {  to  1  inch  above  the 
bottom.  In  the  centre  of  the  lid  D,  which  lies  loosely  upon 
the  vat,  is  an  aperture,  0  ;  in  a  second  aperture  a  thermometer, 
r,  is  inserted,  whose  bulb  dips  into  the  fluid  ;  and  in  a  third 
aperture  is  fitted  a  glass  funnel,  R,  reaching  nearly  to  the  bot- 
tom of  the  vat. 

The  operation  in  such  a  factor}^  commences  with  the  cul- 
ture of  the  vinegar  ferment.  For  this  purpose  as  many  shal- 
low porcelain  plates  as  there  are  vats  are  placed  upon  the 
table,  and  wine  to  the  depth  of  J  to  f  inch  is  poured  in  each. 
The  room  should  be  heated  and  kept  at  a  temperature  of  86° 
F.  The  manner  of  the  development  of  the  vinegar  ferment 
upon  the  fluid  in  the  plates  as  well  as  the  precautions  which 
have  to  be  taken  has  already  been  described.  In  the  com- 
mencement of  the  operation  the  culture  of  the  ferment  requires 
great  attention,  it  being  frequently  disturbed  by  the  develop- 
ment of  mold  ferment,  but  when  the  factory  is  once  in  proper 
working  condition  it  is  readily  effected  because  the  air  of  the 
workroom  then  contains  a  large  quantity  of  the  ferment,  which 
rapidly  propagates  on  coming  in  contact  with  a  fluid  favor- 
able for  its  development. 

The  vats  are  charged  by  allowing  the  fluid  to  be  converted 
into  vinegar  to  run  in  until  it  begins  to  pass  out  through  g. 
The  impregnation  with  ferment  is  then  effected  by  carefully 
emptying  the  contents  of  one  of  the  plates  upon  the  surface  of 
the  fluid,  so  that  the  greater  portion  remains  floating  upon  it. 
Finally  the  lid  is  placed  upon  the  vat  and  the  latter  left  to 
itself. 

The  ferment  soon  covers  the  entire  surface  of  the  fluid  in 
the  vat,  and  the  commencement  of  the  process  of  oxidation  is 
in  a  short  time  recognized  by  the  rise  of  the  thermometer  dip- 
ping into  the  fluid.  As  long  as  the  quantity  of  alcohol  in  the 
fluid  is  comparatively  large,  the  process  of  the  formation  of 
acetic  acid  and  the  propagation  of  the  ferment  takes  place 
very  rapidly  and  the  thermometer  rises  constantly  ;  but  with 


206  MANUFACTURE    OF    VINEGAR. 

an  increase  in  the  quantity  of  acetic  acid  these  processes  become 
slower,  which  is  indicated  by  a  fall  in  the  temperature  of  the 
fluid.  The  energy  of  the  process  must,  however,  not  be  al- 
lowed to  sink  below  a  certain  limit,  care  being  taken  to  keep 
it  up  by  raising  the  temperature  of  the  workroom,  but  not 
higher  than  is  absolutely  necessary  for  the  correct  working, 
as  otherwise  there  would  be  a  loss  of  acetic  acid  or  alcohol  by 
evaporation. 

The  most  convenient  and  business-like  manner  of  operating 
a  factory  arranged  as  above  described  is  to  simultaneously 
charge  all  the  vats  with  alcoholic  liquid,  it  being  then  entirely 
in  one's  power  to  regulate  the  heating  of  the  workroom  accord- 
ing to  the  indications  of  the  thermometer  dipping  into  the 
fluid.  If,  for  instance,  the  operation  commences  at  77°  F.,  the 
thermometer  will  soon  be  observed  to  rise  even  if  the  tempera- 
ture of  the  workroom  remains  unchanged.  By  the  oxidation 
of  the  alcohol  sufficient  heat  is  liberated  to  increase  the  tem- 
perature of  the  fluid  to  above  95°  F.  It  is,  however,  advisable 
not  to  allow  it  to  rise  above  86°  or  90°  F.,  as  otherwise  the 
losses  by  evaporation  are  too  great.  Hence,  if  the  fluid  reaches 
this  limit  of  temperature  the  heating  of  the  workroom  is  so 
regulated  as  to  prevent  a  further  rise  of  the  thermometer,  and 
a  constant  temperature  is  maintained  for  several  days  until  it 
commences  to  fall  almost  simultaneously  in  all  the  vats.  This 
fall  in  the  temperature,  as  previously  mentioned,  is  an  indica- 
tion of  the  fluid  now  containing  a  comparatively  large  amount 
of  acetic  acid  and  of  the  slow  oxidation  of  the  remaining  alco- 
hol. In  order  to  maintain  the  most  favorable  conditions  for 
the  efficacy  of  the  vinegar  ferment  and  to  smoothly  and  rapidly 
complete  the  process  the  workroom  is  now  so  heated  as  to 
show  a  constant  temperature  of  86°  F.  as  long  as  the  fluid  re- 
mains in  the  vat. 

Side  by  side  with  the  observation  of  the  statements  of  the 
thermometer  a  chemical  examination  of  the  fluid  has  to  be 
carried  on,  this  examination  gaining  in  importance  the  further 
the  formation  of  vinegar  progresses.  If  the  content  of  alcohol 


MANUFACTURE    OF    WINE    VINEGAR.  207 

in  the  wine  to  be  worked  is  known,  the  test  is  up  to  a  certain 
stage  limited  to  the  determination  of  the  acetic  acid,  but  if  the 
process  has  so  far  advanced  that  the  fluid  contains  scarcely  1 
per  cent,  of  alcohol,  the  latter  has  also  to  be  determined  by 
means  of  the  ebullioscope  which  will  be  described  later  on. 
From  this  moment  on  the  course  of  the  process  must  be  very 
carefully  controlled,  and  interrupted  when  still  0.15  or  at  the 
utmost  0.2  per  cent,  of  alcohol  is  present.  This  small  amount 
of  unchanged  alcohol  exerts  a  favorable  effect  upon  the  quality 
of  the  vinegar,  acetic  ether  being  formed  from  it  and  a  corre- 
sponding quantity  of  acetic  acid  during  the  time  the  vinegar 
has  to  be  stored. 

The  interruption  of  the  process  is  best  effected  by  separating 
the  fluid  from  the  layer  of  ferment  floating  upon  it.  The  stop- 
cock, H,  Fig.  48,  is  opened  and  left  open  as  long  as  fluid  runs 
out.  A  layer  of  vinegar  about  j  to  1  inch  deep  upon  which 
floats  the  vinegar  ferment,  remains  in  the  vat,  and  the  stop- 
cock being  closed  a  fresh  supply  of  alcoholic  liquid  is  intro- 
duced through  the  funnel  R  until  it  begins  to  run  out  through 
g.  The  process  then  commences  anew  in  the  manner  above 
described. 

Theoretically  unlimited  quantities  of  wine  could  be  con- 
verted into  vinegar  by  means  of  such  an  apparatus,  as  the 
vinegar  ferment  which  floats  upon  the  fluid  that  remains  in 
the  vat,  rapidly  propagates  upon  the  fresh  supply  of  wine  and 
converts  it  into  vinegar.  In  practice  an  occasional  short  in- 
terruption of  the  process  is,  however,  necessary.  During  the 
conversion  of  the  wine  the  greater  portion  of  albuminous  sub- 
stances held  in  solution  in  it  separates  as  flakes,  and,  further, 
a  portion  of  the  vinegar  ferment  sinks  below  the  level  of  the 
fluid  and  assumes  the  form  of  the  flaky  masses  called  mother 
of  vinegar.  The  result  after  a  number  of  operations  is  a  slimy 
sediment,  which  finally  accumulates  to  such  an  extent  that  it 
has  to  be  removed.  This  is  effected,  after  the  finished  vinegar 
is  drawn  off,  by  opening  the  tap-hole  Z,  and  removing  the 
slimy  mass  by  means  of  a  broom  or  crutch.  The  vat  is  then 


208  MANUFACTURE    OF    VINEGAR. 

thoroughly  washed  with  water  and  can  be  immediately  re- 
charged with  wine.  The  slimy  mass  is  best  collected  in  a  tall 
vat  and  allowed  to  rest.  In  a  few  days  it  separates  into  two 
layers,  the  upper  one  consisting  of  quite  clear  vinegar  which 
can  be  used  for  filling  up  storage-barrels,  and  the  lower  one  of 
a  thickly-fluid  mass  from  which  a  certain  quantity  of  vinegar 
can  be  obtained  by  filtration. 

The  vinegar  drawn  off  from  the  vats  is  brought  into  storage 
barrels  which  are  filled  up  to  the  bung  and  closed  air-tight. 
The  volume  of  the  vinegar  decreasing  by  cooling,  the  barrels 
must  from  time  to  time  be  examined  and  kept  filled  up  to  the 
bung-hole.  While  stored  in  the  barrels  the  vinegar  almost 
completely  clarifies^  and  by  carefully  siphoning  off  the  clear 
portion,  it  can  be  at  once  brought  into  commerce  without 
further  treatment.  When  a  considerable  quantity  of  slimy 
sediment  has  collected  in  the  storage-barrels,  it  is  drawn  off 
and  brought  into  the  above-mentioned  clarifying  vat,>  or  is 
clarified  by  filtration. 

In  case  of  disturbances  in  the  production  by  the  appearance 
of  mold  ferment  or  vinegar  eels,  the  process  once  commenced 
must  be  carried  through  as  well  as  possible,  and  then  the  en- 
tire operation  interrupted  for  the  purpose  of  thoroughly  cleans- 
ing the  vessels  by  washing  with  boiling  water  or  steaming. 
Under  no  circumstances  should  it  be  attempted  to  continue 
working  with  vats  infected  with  mold  or  vinegar  eels,  as  it 
would  only  lead  to  a  considerable  loss  of  material,  and  the 
cleansing  of  the  vessels  which  would  have  to  be  finally  done, 
would  be  more  difficult. 

If  the  vinegar  has  been  made  from  clear,  ripe  wine,  it  will 
generally  come  quite  clear  from  the  apparatus  used  for  its  pro- 
duction. Should  it  be  turbid,  as  may  sometimes  happen,  it 
has  to  be  filtered  through  a  bag  or  other  filter  as  described  on 
p.  156.  The  turbidity  is  caused  by  various  substances  sepa- 
rated during  the  formation  of  the  vinegar.  Vinegar  is  much 
more  difficult  to  fine  than  wine  and  for  this  reason  alone,  only 
clarified,  ripe  wines  should  be  used  for  its  production.  The 


MANUFACTURE    OF    WINE    VINEGAR.  209 

simplest  method  to  clarify  the  vinegar  is  to  store  it  for  several 
weeks  in  a  cool  cellar  in  casks  filled  up  to  the  bung.  The 
•greater  portion  of  the  vinegar  can  then  Tbe  drawn  off  perfectly 
clear  and  only  the  last  portion  will  require  filtering. 

The  filtered  vinegar  is  brought  into  clean  casks  and  stored 
in  a  cool  cellar.  However,  while  thus  stored  it  may  some- 
times depreciate  in  quality  and  strength  by  unfavorable  con- 
ditions of  temperature  or  handling,  such  depreciation  being 
indicated  by  a  change  in  the  aroma,  and  the  acid  taste  loses 
its  sharpness  and  shows  a  peculiar  insipidity.  The  cause  of 
this  alteration  may  be  attributed  to  the  decomposition  of  the 
tartaric  and  malic  acids  in  the  vinegar  by  a  ferment.  The 
only  sure  remedy  for  this  and  all  other  alterations  is  to  steri- 
lize the  vinegar  by  heating  to  140°  F.  The  apparatus,  Fig. 
46,  p.  197,  for  pasteurizing  wine,  or  any  other  form  of  pasteur- 
izer may  be  used  for  the  purpose.  The  vinegar  should  come 
out  of  the  pasteurizer  cool  and  the  storage-barrels  should  be 
completely  filled,  bunged  tight  and  placed  in  a  cool  cellar. 

Wine  vinegar  acquires  its  special  aroma  only  by  being  stored 
for  several  months.  French  manufacturers  store  their  best 
quality  of  it  for  at  least  one  year  before  offering  it  for  sale  and, 
of  course,  charge  a  good  price. 

When  the  wine  vinegar  has  acquired  a  fine  taste  and  aroma 
by  storing  it  should  be  bottled,  this  being  the  most  profitable 
way  of  selling  it.  As  the  vinegar  should  be  perfectly  bright 
before  racking  it  into  bottles  it  must  first  be  filtered  or  fined. 
Many  manufacturers  pasteurize  the  bottled  vinegar.  An  ap- 
paratus for  this  purpose  *  is  shown  in  Fig.  49.  It  consists  of 
an  iron  receptacle  furnished  with  a  cover  fitting  air-tight,  and 
in  the  interior  with  a  perforated  false  bottom.  The  apparatus 
is  about  5  feet  long,  3  feet  6  inches  wide  and  1J  feet  deep. 
Between  the  perforated  false  bottom  and  the  actual  bottom  is 
a  pipe-system  which  is  connected  by  two  iron  pipes  with  the 
furnace.  The  bottles  are  placed  alongside  each  other  upon  the 

*  German  patent  No.  17970  granted  to  Boldt  &  Vogel,  Hamburg. 

14 


210 


MANUFACTURE    OF    VINEGAR. 


perforated  false  bottom.  Before  placing  them  in  the  appara- 
tus, water  is  admitted  into  the  latter  so  as  to  fill  the  space 
below  the  perforated  false  bottom  and  cover  the  latter.  Fire 
is  then  started  in  the  furnace  and  the  water  commencing  to 
circulate,  steam  is  in  a  short  time  evolved  in  the  apparatus. 
The  temperature  prevailing  in  the  interior  is  indicated  by  a 
thermometer  on  top  of  the  apparatus,  and  pasteurization  can 
thus  be  carried  on  to  any  desired  degree.  Cooling  is  effected 
by  discontinuing  heating  and  opening  the  cover. 

Pasteurized  wine-vinegar  does  not  spoil  if  exposed  to  vary- 

FIG.  49. 


ing  temperatures  or  even  if  kept  in  open  or  improperly  closed 
receptacles.  It  is  free  from  all  kinds  of  ferments  and  vinegar 
eels,  and  is  not  attacked  by  the  spores  of  the  vinegar  ferment 
suspended  in  the  air,  because  the  nutriment  required  for  their 
further  development  has  been  withdrawn. 

Wine-Vinegar  by  the  Quick  Process. — Although  in  making 
wine  vinegar  of  fine  quality,  the  best  results  are  without  doubt 
obtained  by  one  of  the  slow  methods  above  described,  a  very 
good  product  can  be  made  from  clear  wines  in  one  of  the  gen- 
erators previously  described,  that  furnished  with  a  tilting 


MANUFACTURE    OF    WINE    VINEGAR.  211 

trough  being  by  some  manufacturers  preferred  for  the  purpose. 
The  process  is  the  same  as  for  ordinary  vinegar,  the  principal 
conditions  for  smooth  working  being  a  limited  admission  of 
air  below  the  perforated  false  bottom,  the  use  of  perfectly  clear, 
pasteurized  wine,  correct  measuring  of  the  quantity  to  be 
poured  and  its  uniform  distribution,  absolute  cleanliness, 
cleansing  the  perforated  head  every  week  or  two,  according  to 
the  accumulation  of  slime,  and  finally  continuous  working. 
The  last  condition — continuous  working — is  necessary  to  pre- 
vent the  product  from  being  impaired  during  the  rest  at  night 
by  a  decomposition — a  decrease  of  its  most  valuable  properties. 

Wine-vinegar  made  by  the  quick  process  has  less  aroma 
than  that  prepared  by  the  other  method.  However,  by  stor- 
ing it  for  about  three  months  it  gains  in  quality  and  aroma 
so  that  it  can  scarcely  be  distinguished  from  vinegar  made  by 
the  Orleans  method. 

Wine  Vinegar  from  Marc — The  marc  left  after  the  wine  has 
been  pressed  consists  of  the  stems,  skins  and  seeds  of  the  grapes 
and  contains  a  not  unimportant  quantity  of  must.  As,  pre- 
viously described,  by  subjecting  the  marc  with  the  addition  of 
water  or  sugar  solution  to  fermentation  a  wine  is  obtained 
which  forms  an  excellent  material  for  making  vinegar.  How- 
ever, the  marc  may  also  be  directly  used  for  the  purpose. 

The  mass  of  marc  as  it  comes  from  the  press  is  broken  up 
and  put  in  a  pile  where  it  is  left  to  itself  until  it  becomes  warm 
and  acquires  the  odor  of  alcohol  and  acetic  ether.  The  mass 
is  then  shoveled  into  a  vat  and  gently  pressed  together  with  a 
shovel.  For  every  220  Ibs.  of  marc  used,  about  10  quarts  of 
water  are  now  sprinkled  over  the  mass  by  means  of  a  watering- 
pot.  By  the  entrance  of  air  while  shoveling  the  pile  of  marc 
into  the  vat  the  action  of  the  vinegar  ferment  has  been  accel- 
erated and  a  considerable  quantity  of  alcohol  converted  into 
acetic  acid,  which  is  indicated  by  the  stronger  vinegar  odor. 
The  water  permeating  the  marc  almost  completely  displaces 
the  fluid  containing  the  alcohol  and  acetic  acid,  the  latter  run- 
ning off  through  an  aperture  in  the  bottom  of  the  vat.  It  is 


212  MANUFACTURE    OF    VINEGAR. 

collected  in  a  shallow  vessel  placed  in  an  apartment  having 
the  ordinary  temperature  of  a  living-room,  and  is  allowed  to 
rest.  The  vinegar  ferment  present  in  abundance  in  the  fluid 
rises  to  the  surface,  where  it  quickly  propagates  and  converts 
the  remainder  of  the  alcohol  in  the  fluid  into  acetic  acid.  The 
only  difficulty  to  be  overcome  in  preparing  the  vinegar  ac- 
cording to  this  method  is  the  appearance  of  the  mold  ferment 
upon  the  surface  of  the  fluid.  This  can,  however,  be  met  by 
removing  the  growth  of  this  ferment,  which  is  recognized  by 
its  pure  white  color,  by  means  of  a  spoon  as  soon  as  it  has  at- 
tained the  thickness  of  a  few  millimeters.  The  vinegar  fer- 
ment then  commences  to  propagate  and  suppresses  the  further 
growth  of  the  mold  ferment. 

If  the  grapes  originally  used  contained  from  18  to  20  per 
cent,  of  sugar,  the  vinegar  from  the  marc  prepared  according 
to  this  method  shows,  if  not  too  much  water  has  been  used,  a 
content  of  at  least  4  or  5  per  cent,  of  acetic  acid,  and  conse- 
quently is  immediately  fit  for  table  use.  By  long  storing  in 
barrels  kept  filled  up  to  the  bung-holes,  it  acquires  a  flavor 
resembling  that  of  vinegar  prepared  from  wine. 

On  account  of  the  simplipity  and  the  slight  expense  con- 
nected with  it,  the  above-described  process  is  especially  adapted 
for  making  vinegar  for  household  use.  For  industrial  pur- 
poses it  is,  however,  more  advantageous  to  prepare  wine  from 
the  marc  as  described  on  p.  190,  and  convert  the  product  thus 
obtained  into  vinegar. 


CHEMICAL    EXAMINATION    OF    RAW    MATERIALS.  213 

CHAPTER  XIX. 

CHEMICAL    EXAMINATION    OF    THE    RAW    MATERIALS    AND    CON- 
TROL   OF    THE    OPERATIONS    IN    A    VINEGAR    FACTORY. 

Determination  of  Sugar. — The  sacchariferous  materials  used 
by  the  vinegar  manufacturer  are  either  whiskey-mashes,  malt- 
extracts,  or  must  prepared  from  wine-marc,  apples,  etc.  The 
determination  of  sugar  contained  in  these  fluids  is  effected  by 
means  of  various  instruments,  which  are  really  hydrometers, 
with  different  names  and  graduations.  The  instruments  mostly 
used  for  the  determination  of  sugar  in  whiskey-mashes  and 
malt  worts  are  known  as  saccharometers,  and  directly  indicate 
the  content  of  sugar  in  the  fluid  in  per  cent.  A  similar  in- 
strument, known  as  the  must-aerometer,  serves  for  the  determi- 
nation of  the  content  of  sugar  in  grape-must.  According  to 
the  arrangement  of  their  scales,  the  must-aerometers  indicate 
either  direct  sugar  per  cent., 'or  degrees ;  in  the  latter  case  the 
use  of  special  tables  accompanying  the  instrument  is  required 
for  finding  the  per  cent,  of  sugar  corresponding  to  a  certain 
number  of  degrees. 

No  special  saccharometer  for  fruit-must  having  as  yet  been 
constructed,  the  determination  of  the  content  of  sugar  has  to 
be  effected  either  by  a  tedious  method  unsuitable  for  practice, 
or,  what  can  be  more  quickly  done,  by  fermenting  a  sample 
of  the  respective  must,  and  after  determining  the  quantity  of 
alcohol,  ascertaining  from  it  tha  content  of  sugar. 

In  place  of  special  saccharometers  or  must-areometers,  an 
ordinary  areometer  indicating  the  specific  gravity  can  also  be 
used,  and  the  content  of  sugar  corresponding  to  a  certain 
specific  gravity  found  from  a  reducing  table.  Tables  X  to 
XIII  at  the  end  of  this  volume  give  the  content  of  sugar  espe- 
cially for  wine-must,  but  also  with  sufficient  accuracy  for  apple 
or  pear-must,  according  to  the  statements  of  the  respective 
must-aerometers. 


214  MANUFACTURE    OF    VINEGAR. 

Determination  of  Alcohol. — In  a  factory  using  commercial 
spirits  of  wine  as  the  fundamental  material  for  making  vine- 
gar, the  percentage  of  absolute  alcohol  contained  in  it  has  to 
be  accurately  determined  in  order  to  enable  one  to  correctly 
calculate,  in  the  manner  explained  on  p.  109,  the  quantity  of 
water  required  for  the  preparation  of  alcoholic  liquid  of  de- 
termined strength. 

For  the  determination  of  the  content  of  alcohol  in  pure 
spirits  of  wine  consisting  only  of  water  and  alcohol,  instru- 
ments called  alcoholometers  are  generally  used,  they  indicating 
the  volumes  of  alcohol  contained  in  100  volumes  of  the  spirits 
of  wine.  They  are,  however,  not  suited  for  this  purpose  when, 
as  is  frequently  the  case  in  a  vinegar  factory,  the  spirit  of  wine 
contains  other  bodies  besides  water  and  alcohol.  In  this  case, 
either  the  alcohol  contained  in  a  sample  has  to  be  distilled  off, 
and  after  determining  its  strength  by  the  alcoholometer,  the 
content  of  alcohol  in  the  total  quantity  of  fluid  ascertained  by 
calculation,  or  the  determination  is  effected  in  a  short  time 
and  with  sufficient  accuracy  for  practical  purposes  by  the  use 
of  a  special  apparatus. 

Determination  of  the  Alcohol  with  the  Alcoholometer. — For  the 
vinegar  manufacturer  the  alcoholometer  is  an  important  in- 
strument in  so  far  as  it  serves  for  quickly  ascertaining  the  de- 
grees of  the  spirits  of  wine  used.  It  is  best  to  use  an  instru- 
ment which  is  combined  with  a  thermometer,  one  being  thus 
enabled  to  ascertain  the  temperature  of  the  fluid  simultane- 
ously with  reading  off  the  statement  of  the  alcoholometer. 
Tables  I  to  VIII  appended  to  this  work  give  the  necessary  as- 
sistance for  the  determination  of  the  actual  content  of  alcohol 
in  a  fluid  whose  temperature  is  above  or  below  the  normal 
temperature  (59°  F.). 

For  examining  fluids  with  a  very  small  content  of  alcohol, 
alcoholometers  have  been  constructed  which  accurately  indi- 
cate at  least  0.1  percent.  For  the  manufacture  of  vinegar, 
four  alcoholometers  will,  as  a  rule,  suffice.  They  should  be 
so  selected  that  one  is  to  be  used  for  fluids  with  from  0  to  4 


CHEMICAL    EXAMINATION    OP    RAW    MATERIALS.  215 

per  cent,  of  alcohol,  the  second  for  indicating  4  to  8  per  cent., 
the  third  8  to  12  per  cent.,  and  the  fourth  12  to  1C  per  cent. 
The  scale  of  such  alcoholometers  comprising  only  4  per  cent, 
each,  is  sufficiently  large  to  allow  of  the  easy  reading  off  of 
one-tenth  per  cent.  These  instruments  serve  for  the  determi- 
nation of  the  content  of  alcohol  in  alcoholic  liquid  consisting 
only  of  spirits  of  wine  and  water,  and  are  used  in  examining 
the  progress  of  the  formation  of  vinegar  during  manufacture. 

Determination  of  the  Alcohol  by  the  Distilling  Test — The  con- 
tent of  alcohol  in  a  fluid  containing  other  bodies  besides  alco- 
hol and  water  cannot  be  directly  determined  by  means  of  the 
alcoholometer,  as  the  statement  of  the  latter  would  be  incor- 
rect on  account  of  the  foreign  bodies  exerting  a  considerable 
influence  upon  the  specific  gravity.  Hence,  the  content  of 
alcohol  in  alcoholic  liquid  containing  a  certain  quantity  of 
acetic  acid,  or  fermented  whiskey-mash,  beer,  wine,  etc.,  can- 
not be  ascertained  by  immersing  the  alcoholometer  in  the  re- 
spective fluid.  In  order  to  determine  the  content  of  alcohol 
in  such  a  fluid  a  determined  volume  of  it  is  subjected  to  dis- 
tillation, and  the  latter  continued  until  it  may  be  supposed 
that  all  the  alcohol  present  is  volatilized  and  again  condensed 
in  a  suitable  cooling  apparatus.  By  diluting  the  fluid  distilled 
over  with  sufficient  water  to  restore  it  to  the  volume  of  the 
fluid  originally  used  and  immersing  the  alcoholometer  the 
content  of  alcohol  is  determined. 

A  rapid  and  at  the  same  time  accurate  execution  of  all  ex- 
aminations being  of  great  importance  in  practice,  a  suitable 
apparatus  should  be  used  for  the  distilling  test.  Such  an  ap- 
paratus is  shown  in  Fig.  50.  It  consists  of  a  glass  boiling 
flask,  K,  having  a  capacity  of  \  liter  in  which  sits  by  means 
of  a  perforated  cork  a  glass  tube,  E,  which  is  about  f  inch  in 
diameter  and  7f  inches  in  length.  On  top  this  tube  is  closed 
by  a  perforated  cork.  From  the  latter  a  glass  tube  bent  twice 
at  a  right  angle  leads  to  a  cooling-coil,  which  is  placed  in  a 
vessel  F,  filled  with  water,  and  terminates  over  a  graduated 
cylindrical  glass  vessel  G.  The  uppermost  mark  on  G  indi- 


216 


MANUFACTURE    OF    VINEGAR. 


cates  the  height  to  which  the  vessel  must  be  filled  to  contain 
^  liter  =  500  cubic  centimeters.  Generally  vessels  are  used 
which  are  so 'graduated  that  the  distance  between  two  marks 
is  equal  to  2-V  liter  or  50  cubic  centimeters.  The  boiling-flask 
stands  upon  a  plate  of  thin  sheet-iron  (to  prevent  bursting 
from  an  immediate  contact  with  the  flame),  and  together  with 
the  cooling  vessel  is  screwed  to  a  suitable  support. 

In  distilling  a  fluid  containing  acetic  acid  the  vapors  of  the 
latter  pass  over  together  with  those  of  alcohol  and  water,  and 
consequently,  the  statement  of  the  alcoholometer  would  be  in- 

FIG.  50. 


correct.  This  is  overcome  by  placing  a  few  pieces  of  chalk 
the  size  of  a  hazelnut  in  the  tube  R.  By  the  vapors  coming  in 
contact  with  the  chalk  the  acetic  acid  is  fixed  to  the  lime  con- 
tained in  it,  not  a  trace  reaching  the  cooling  vessel. 

The  manner  of  executing  the  test  with  this  apparatus  is  as  fol- 
lows :  Fill  the  vessel  G  to  the  uppermost  mark  with  the  fluid 
whose  content  of  alcohol  is  to  be  examined,  then  pour  it  into 
the  boiling  flask  K,  rinse  out  G  with  water,  and  after  pouring 
the  rinsing  water  into  K,  put  the  apparatus  together  as  shown 
in  the  illustration.  The  contents  of  K  are  then  heated  to  boil- 


CHEMICAL    EXAMINATION    OF    RAW    MATERIALS.  217 

ing  by  a  spirit  or  gas  flame  under  the  sheet-iron  plate  upon 
which  Crests,  the  flame  being  so  regulated  that  the  distillate 
flows  in  drops  into  G(.  By  too  strong  heating  the  contents  of 
K  might  foam  up  and  pass  into  (r,  which  would  necessitate  a 
repetition  of  the  experiment  with  another  quantity  of  fluid. 
Wine,  beer,  and  whiskey-mashes  frequently  foam  up  on  heat- 
ing, which  can,  however,  be  almost  completely  overcome  by  the 
addition  of  a  small  quantity  of  tannin  solution  to  the  contents 
inK. 

The  heating  of  the  boiling  flask  is  continued  until  sufficient 
fluid  is  distilled  over  into  G  to  fill  it  from  one  third  to  one  half 
full,  this  being  a  sure  indication  of  all  the  alcohol  present  in 
the  fluid  having  passed  over.  The  flame  is  then  removed,  the 
vessel  G  filled  to  the  uppermost  mark  with  distilled  water,  and 
the  fluids  intimately  mixed  by  shaking,  the  mouth  of  G  being 
closed  by  the  hand.  The  fluid  now  contained  in  G  consists 
only  of  water  and  alcohol,  and  its  volume  is  equal  to  that  of 
the  fluid  originally  used.  By  testing  the  fluid  with  an  alco- 
holometer the  content  of  alcohol  found  corresponds  exactly 
to  that  possessed  by  the  fluid  examined — alcoholic  liquid, 
beer,  fermented  whiskey-mash,  etc. 

Determination  of  the  Alcohol  by  Means  of  the  Ebullioscope. 
Many  determinations  of  the  content  of  alcohol  in  the  alcoholic 
fluid  having  to  be  made  in  a  well-conducted  vinegar  factory, 
the  above-described  distilling  test  is  objectionable  on  account 
of  the  time  (about  twenty  minutes)  required  for  its  execution. 
Good  results  are,  however,  obtained  by  the  use  of  the  ebullios- 
cope  and,  but  a  few  minutes  being  required  for  the  test  with 
this  apparatus,  it  can  be  frequently  repeated,  and  thus  even  a 
more  accurate  idea  of  the  working  of  the  generators  obtained 
than  is  possible  with  a  single  determination  by  the  distilling 
test.  The  apparatus  is  very  simple,  is  easily  managed,  and 
allows,  without  the  use  of  an  sero meter  or  table,  of  the  direct 
reading-off  of  the  content  of  alcohol  in  a  fluid  containing  not 
much  over  12  per  cent.  It  is  much  used  in  France  for  the  ex- 
amination of  wine.  The  principle  of  the  apparatus  is  based 


218  MANUFACTURE    OF    VINEGAR. 

upon  the  initial  boiling  point  of  the  fluid  to  be  examined,  an 
alcoholic  fluid  boiling  at  a  lower  temperature  the  more  alcohol 
it  contains.  For  instance,  wine  with — 

12  per  cent,  by  volume  of  alcohol  boils  at  196.7°  F. 
10        "  "  198.3°  F. 

8         "  201.0°  F. 

5         "  203.3°  F. 

Fig.  51  shows  Vidal-Malligaud's  ebullioscope.  To  a  round 
cast-iron  stand  is  screwed  a  thick-walled  brass  cup  which  ex- 
pands somewhat  towards  the  top  ;  a  screw-thread  is  cut  in  the 
upper  edge.  A  hollow-brass  ring  is  soldered  into  the  cup  near 
its  base,  the  one  end  of  the  ring  entering  it  somewhat  higher 
than  the  other.  On  filling  the  cup  with  the  fluid  to  be  ex- 
amined this  hollow  ring  also  becomes  filled.  On  the  one  side 
the  ring  carries  a  small  sheet-iron  chimney,  and  by  placing  a 
small  spirit  lamp  under  this  the  fluid  in  the  cup  is  heated, 
this  arrangement  securing  a  quick  circulation  of  the  fluid 
during  heating.  Upon  the  upper  edge  of  the  cup  a  lid  is 
screwed,  in  which  a  thermometer  is  inserted  air-tight.  The 
mercury  bulb  of  the  thermometer  is  on  the  lower  side  of  the 
lid  and,  in  determining  the  boiling-point,  dips  into  the  fluid. 
The  tube  of  the  thermometer  is  bent  at  a  right  angle  outside 
the  lid,  the  latter  carrying  the  scale,  which  is  divided  not  into 
degrees  but  in  per  cent,  by  volume  of  alcohol.  The  scale  can 
be  shifted  upon  a  supporting  plate  so  that  it  can  be  fixed  at 
any  desired  place,  and,  consequently,  also  so  that  the  ther- 
mometer when  dipped  into  boiling  water  indicates  0.  The 
scale  is  secured  by  small  screws.  Into  a  second  aperture  in 
the  lid  is  screwed  the  cooling-pipe,  which  is  surrounded  by  a 
wide  brass  tube  for  the  reception  of  the  cooling  water.  During 
the  determination  of  the  alcohol,  which  requires  about  ten 
minutes,  the  cooling  water  need  not  be  renewed,  the  boiling 
point  remaining  constant  during  the  short  time  (one  or  two 
minutes)  necessary  for  making  the  observation.  In  heating 
wine,  the  gases  and  besides  a  few  light  volatile  varieties  of 


CHEMICAL    EXAMINATION    OF    RAW    MATERIALS. 


219 


ether,  as  acetic  ether,  aldehyde,  etbylamine,  propylamine,  and 
similar  combinations  escape  through  the  cooling  pipe,  which 
is  open  on  top,  and  in  heating  beer,  carbonic  acid.  For  the 
determination  of  the  alcohol  in  sacchariferous  wines,  the  ebul- 
lioscope  is  less  adapted,  nor  does  it  give  accurate  results  with 
the  use  of  dilute  wines. 

It  has  been  ascertained  by  the  French  Academy  that  the 


FIG.  51 


JL 


statements  of  the  ebullioscope  as  regards  the  quantity  of  alco- 
hol in  the  wine  differ  on  an  average  J  per  cent,  from  those 
found  by  accurate  distillation.  The  entire  apparatus  with  the 
exception  of  the  thermometer  being  of  metal,  it  is  not  liable  to 
breakage.  The  mercury  bulb  of  the  thermomter  is  compara- 
tively large.  For  the  vinegar  manufacturer  the  ebullioscope  is 
a  very  valuable  instrument,  as  it  enables  him  to  accurately 


220  MANUFACTURE  OF  VINEGAR. 

determine  to  within  %  per  cent,  the  content  of  alcohol  in  a  fluid 
in  a  shorter  time  than  is  possible  with  any  other  instrument. 
Its  use  is  especially  recommended  when  the  working  of  one  or 
more  generators  is  to  be  ascertained  in  a  short  time,  perfectly 
reliable  results  being  obtained  in  connection  with  the  deter- 
mination of  the  acid  by  titration. 

Determination  of  the  Content  of  Acetic  Anhydride  in  Vinegar 
or  Acetometry.  The  content  of  acetic  acid  in  vinegar  is  some- 
times ascertained  by  a  species  of  hydrometer  termed  an 
acetometer.  The  statements  of  these  instruments  are,  however, 
very  unreliable.  Vinegar  made  from  dilute  alcohol  or  ripe 
wines  in  which  no  great  excess  of  albuminous  or  other  matter 
is  present  might  to  a  certain  limit  be  tested  with  sufficient 
accuracy  by  the  acetometer,  but  vinegars  made  from  malt, 
poor  wines,  and  such  liquids  as  contain  an  excess  of  organic 
matters,  do  not  admit  of  being  tested  with  the  required  degree 
of  accuracy  by  this  method,  since  the  apparent  quantity  of 
real  acetic  acid  is  increased  by  the  presence  of  foreign  bodies 
which  add  to  the  density  of  the  liquid.  In  some  cases  the 
vinegar  is  saturated  with  chalk  or  milk  of  lime,  the  solution 
filtered,  and  the  specific  gravity  of  the  acetate  of  lime  liquor 
ascertained,  by  which  a  nearer  approximation  is  arrived  at 
than  by  the  direct  testing  of  the  vinegar,  yet  implicit  reliance 
cannot  be  placed  on  either  of  these  two  methods. 

The  best  method  of  ascertaining  the  percentage  of  acetic 
acid  in  vinegar  is  by  titration  or  volumetric  analysis.  For 
the  execution  of  the  test  a  few  instruments  are  required, 
namely,  a  burette  and  pipette.  The  latter  is  filled  by  dipping 
the  lower  end  of  it  into  the  fluid  and  sucking  on  the  upper 
end  with  the  mouth  until  the  fluid  has  ascended  nearly  to  the 
.  top.  The  upper  end  is  then  quickly  closed  with  the  index 
finger  of  the  right  hand.  By  slightly  lifting  the  finger  the 
liquid  is  then  allowed  to  flow  off  by  drops  until  its  level  has 
reached  a  mark  above  the  convex  expansion  of  the  instru- 
ment, when  it  will  contain  exactly  the  number  of  cubic  centi- 
meters indicated  opposite  to  the  mark. 


CHEMICAL    EXAMINATION    OF    RAW    MATERIALS.  221 

The  burette  is  a  cylindrical  glass  tube  open  on  the  top.  It 
is  graduated,  commencing  from  the  top,  into  whole,  one-tenth 
and  one-fifth  cubic  centimeters.  The  lower  end  of  the  tube  is 
drawn  out  to  a  somewhat  distended  point  so  as  to  allow  a 
rubber  tube  to  be  drawn  over  it  and  securely  fastened.  In 
the  lower  end  a  glass  tube  drawn  out  to  a  fine  point  is  inserted. 
The  rubber  tube  is  compressed  in  the  center  by  a  pinch-cock 
or  clip,  whereby  the  lower  end  is  closed.  The  burette  is  filled 
with  fluid  from  above  by  means  of  a  small  funnel.  By  a 
quick,  strong  pressure  upon  the  handle-joint  of  the  clip,  some 
liquid  is  then  allowed  to  flow  in  a  jet  into  a  vessel.  By  this 
the  tube  below  the  clip  is  filled  with  liquid  and  the  air  con- 
tained in  it  expelled.  By  a  slight  or  stronger  pressure  the 
liquid  can,  after  some  experience,  be  ejected  in  drops  or  in  a 
stronger  jet.  The  number  of  cubic  centimeters  which  have 
been  allowed  to  flow  out  can  be  readily  read  off  by  keeping 
the  surface  of  the  fluid  in  the  tube  on  a  level  with  the  eye. 
The  test  liquor  generally  used  is  normal  caustic  soda  solution, 
one  cubic  centimeter  of  it  corresponding  to  0.06  gramme  of 
acetic  anhydride,  and  for  especially  accurate  determinations 
decinormal  solution,  one  cubic  centimeter  of  it  corresponding 
to  0.006  gramme  of  acetic  anhydride  and  -^  cubic  centimeter 
to  0.0006  gramme. 

For  determining  the  acetic  acid  the  burette  is  filled  to  the  0 
point  with  soda  solution.  A  corresponding  quantity  of  vinegar 
is  then  accurately  measured  off  by  means  of  the  pipette,  and 
after  bringing  it  into  a  beaker,  colored  red  by  the  addition  of 
one  or  two  drops  of  litmus  tincture  and  diluted  with  four  or  six 
times  its  quantity  of  distilled  water.  The  beaker  is  placed  upon 
a  white  support  under  the  burette  and  the  soda  solution  in  the 
latter  ejected  in  a  strong  jet  by  pressing  with  the  right  hand 
the  handle-joint  of  the  clip,  the  fluid  being  constantly  agitated 
by  gently  swinging  the  beaker  with  the  left.  The  inflow  of 
soda  solution  is  interrupted  as  soon  as  a  blue  coloration  on  the 
point  where  it  runs  in  is  observed.  After  thoroughly  stirring 
the  fluid  with  a  glass  rod,  the  soda  solution  is  again  allowed  to 


222 


MANUFACTURE    OF    VINEGAR. 


FIG.  52. 


run  in,  but  now  drop  by  drop,  the  fluid  being  stirred  after  the 
addition  of  each  drop.  This  is  continued  until  the  fluid  has 
acquired  a  violet  color  with  a  strong  reddish  shade,  and  the 
addition  of  one  drop  more  of  soda  solution  changes  the  color 
to  blue.  The  appearance  of  the  violet  coloration  is  called  the 
neutralizing  point,  while  the  change  of  color  from  violet  to  blue 
indicates  that  the  fluid  is  now  neutral,  i.  e.,  contains  neither 
free  acetic  acid  nor  an  excess  of  caustic  soda.  The  determina- 
tion is  based  upon  the  coloring  substance  of  litmus  appearing 
red  in  acid,  violet  in  neutral,  and  blue  in  alkaline  solutions. 

Instead  of  soda  test  liquor,  a  solution  of  ammonia  is  some- 
times used  to  saturate  the  acid.  The  solution  is  prepared  by 
adding  water  to  concentrated  ammonia  till  the  specific  gravity 
is  0.992  ;  1000  grains  of  this  dilute  ammonia 
contain  one  equivalent  of  ammonia,  which  is 
capable  of  saturating  one  equivalent  of  acetic 
acid.  The  application  of  this  test  is  similar 
to  that  already  described. 

There  is  some  difficulty  in  preserving  the 
dilute  ammonia  of  the  same  strength,  which 
is  an  objection  to  its  use ;  but  a  uniformity  of 
concentration  may  be  insured  by  introducing 
into  the  bottle  two  glass  hydrometer  bulbs  so 
-  adjusted  that  one  remains  barely  touching  at 
the  bottom,  and  the  other  floats  just  under 
the  surface  of  the  liquid  as  long  as  the  test- 
liquor  retains  the  proper  strength.  If  a  part 
of  the  ammonia  volatilizes,  the  specific  gravity 
of  the  liquor  will  become  proportionately 
greater,  and  the  glass  bulbs  rise  ;  the  lower  one 
higher  from  the  bottom,  and  the  upper  one 
partly  above  the  surface.  When  this  happens, 
more  strong  ammonia  is  added,  till  the  hydro- 
static drops  are  properly  readjusted. 

Determinations  of  acetic  acid  by  titration  having  to  be  fre- 
quently executed    in  a  vinegar   factory,    it   is    advisable   to 


CHEMICAL    EXAMINATION    OP    RAW    MATERIALS.  223 

use  an  apparatus  which  will  facilitate  the  operation.  Such 
an  apparatus  is  shown  in  Fig.  52.  Upon  a  table  stands  a 
two-liter  flask  holding  the  normal  soda  solution.  The  flask  is 
closed  air-tight  by  a  cork  provided  with  three  perforations. 
In  one  of  these  perforations  is  inserted  a  glass  tube,  A,  in 
the  lower  end  of  which  is  a  stopper  of  cotton  upon  which 
are  placed  small  pieces  of  burnt  lime.  On  top,  the  tube  is 
closed  by  a  glass  tube  drawn  out  to  a  fine  point.  Through 
another  of  these  perforations  passes  a  glass  tube,  R,  bent  twice 
at  a  right  angle  and  reaching  to  the  bottom  of  the  flask.  The 
portion  of  this  tube  outside  of  the  flask,  as  will  be  seen  in  the 
illustration,  is  somewhat  longer  than  that  in  the  flask,  and, 
consequently,  the  tube  forms  a  siphon.  The  outside  portion 
of  this  tube  is  connected  by  a  short  rubber  tube  with  the  upper 
portion  of  the  burette  B.  The  latter  is  secured  in  a  vertical 
position  by  two  rods  placed  on  the  stand  holding  the  flask. 
Below  the  burette  is  connected  with  a  short  rubber  tube  in 
which  is  inserted  a  glass-tube  drawn  out  to  a  fine  point.  On 
the  side  near  the  top  of  the  burette  is  a  small  tube  bent  at  a 
right  angle,  which  is  connected  by  a  short  rubber  tube  with  the 
tube  L,  the  latter  reaching  only  to  below  the  edge  of  the  cork. 
Above  and  below  the  burette  is  closed  by  the  clips  Q  andQ,. 
For  working  with  the  apparatus  the  flask  is  filled  with  nor- 
mal soda  solution  and  the  cork  inserted  air-tight  after  remov- 
ing from  it  the  tube  A,  and  substituting  for  it  a  small  glass- 
tube.  Now  open  the  upper  clip  Q  and  blow  vigorously  through 
the  glass-tube  substituted  for  A,  whereby  the  fluid  is  forced 
through  the  tube  R  into  the  burette.  This  being  done,  cease 
to  press  upon  Q,  whereby  the  latter  closes  and  stops  a  further 
discharge  of  the  fluid.  The  tube,  A,  is  then  placed  in  position. 
By  now  pressing  on  the  clip  Q  the  fluid  passes  into  the  burette, 
the  air  contained  in  the  latter  entering  the  flask  through  the 
tube  L.  The  burette  being  emptied  by  the  discharge  of  the 
fluid  through  Qlt  it  .is  refilled  for  another  determination  of 
acid  by  simply  pressing  on  Q,  and  this  can  be  repeated  as 
long  as  the  flask  contains  soda  solution. 


224  MANUFACTURE    OF    VINEGAR. 

In  discharging  the  fluid  from  the  burette  by  opening  Qv  air 
from  the  outside  passes  into  the  apparatus  through  A.  In 
doing  so  it  must,  however,  pass  through  the  lime  which  fixes 
the  carbonic  acid  contained  in  it,  so  that  the  fluid  in  the  flask 
remains  free  from  carbonic  acid  even  after  standing  for  months. 

The  calculation  of  the  quantity  of  acetic  acid  present  in  the 
vinegar  examined  is  made  as  shown  by  the  following  exam- 
ple : — 

For  10  cubic  centimeters  of  vinegar  were  consumed  70  cubic 
centimeters  of  decinormal  soda  solution. 

One  cubic  centimeter  of  decinormal  soda  solution  being 
equal  to  0.006  gramme  of  acetic  acid,  hence  70  cubic  centi- 
meters=0.42  gramme.  ' 

Now,  as  10  cubic  centimeters  contain  0.42  gramme  of  acetic 
acid,  100  cubic  centimeters  contain  10  times  0.42  gramme  = 
4.2  grammes  .of  acetic  acid  ;  or  the  vinegar  examined  contains 
4.2  per  cent,  by  weight  of  acetic  acid. 

For  the  determination  of  the  strength  of  vinegar  with  suffi- 
cient accuracy  for  manufacturing  and  commercial  purposes  an 
instrument  called  a  vinegar  tester  is  largely  used.  In  the  form 
shown  in  Fig.  53,  as  described  by  Frederic  T.  Bioletti,*  the 
acetic  acid  is  determined  by  the  volume  of  gas  given  off  by 
bicarbonate  of  soda  when  treated  with  a  measured  volume  of 
vinegar. 

"  The  requisite  volume  of  vinegar  is  measured  in  the  small 
glass  tube  A  and  poured  into  the  bottle  B.  A  sufficient 
amount  of  bicarbonate  is  then  taken  with  the  spoon  E  and  in- 
troduced carefully  into  the  bottle.  As  soon  as  the  bottle  is 
tightly  closed  with  the  cork  the  bicarbonate  is  shaken  gradu- 
ally into  the  vinegar  and  immediately  carbonic  acid  gas  com- 
mences- to  be  given  off.  This  gas  passing  through  the  rubber 
tube  forces  the  water  in  the  bottle  D  to  rise  in  the  large  glass 
tube  C.  The  stronger  the  vinegar,  the  more  gas  will  be  given 

*  Grape  Vinegar.     University  of  California  Publications,  College  of  Agricul- 
ture Experiment  Station.     Bulletin  No.  227. 


CHEMICAL    EXAMINATION    OF    RAW    MATERIALS. 


225 


off  and  the  higher  the  water  will  rise  in  the  tube  G.  This 
tube  is  marked  with  numbered  lines.  By  reading  the  num- 
ber of  the  line  nearest  the  level  reached  by  the  water  and  add- 
ing the  estimated  height  above  or  below  this  line,  the  strength 
of  the  vinegar  is  obtained  directly  in  per  cent.  If  the  vinegar 
is  made  from  wine  0.5  per  cent,  must  be  deducted  from  the 
observed  reading  to  allow  for  the  tartaric  acid  of  the  wine. 

FIG.  53. 


"  To  insure  sufficient  accuracy  with  these  instruments  cer- 
tain precautions  are  necessary.  The  bicarbonate  of  soda  sold 
for  cooking  purposes  is  sufficiently  pure.  In  placing  it  in  the 
bottle  care  should  be  taken  that  none  gets  into  the  vinegar 
until  the  bottle  is  securely  corked.  There  must  be  no  leak  in 
the  apparatus.  This  is  determined  by  allowing  the  column 
15 


226  MANUFACTURE    OF    VINEGAR. 

of  water  to  remain  for  a  few  minutes  in  the  cylinder  after 
making  a  determination.  If  the  column  does  not  fall  in  this 
time  there  is  no  leak  of  importance. 

"The  instruments  are  adjusted  for  water  of  ordinary  tem- 
perature. If  the  water  is  either  very  cold  or  very  warm  the 
results  are  inaccurate.  The  following  table  shows  some  of  the 
variations  due  to  the  use  of  too  warm  water." 

KESULTS  OF  VJNEGAR  TESTER  COMPARED  WITH  ACCURATE  ANALYSES 


TT-                                      True 

Reading 

of  vinegar 

tester 

VmeSar-                        acidity. 

.  • 

1 
65°  F. 

75°  F. 

86° 

F. 

1  .   . 

. 
3.02 

1 
2.9 

3.2 

3. 

3 

2      . 

3  .    . 

•-.'.    .       .   .  1        4.55 
6.50 

4.4 

6.4 

4.6 
6.6 

4 
6 

7 
9 

4  .    . 

........  1        7.04 

7.0 

7.4 

7 

7 

5  -    . 

6  .    . 

,  1        8.49 
;    .       .    .       ...                10.15 

8.5 
10.1 

8.7 
10.7 

9 
11 

1 
2 

"  No  temperature  correction  is  possible  as  the  variations  are 
irregular.  At  65°  F!,  as  shown  by  the  table,  the  determina- 
tions agree  very  closely  with  the  results  of  more  accurate  tests. 
There  are  other  sources  of  error  such  as  the  atmospheric  pres- 
sure, the  pressure  of  the  column  of  water  and  the  absorption 
of  gas  by  the  water,  but  they  are  none  of  them  large  enough 
to  be  of  any  significance  to  the  vinegar  maker." 


EXAMINATION    AS    TO    PRESENCE    OF    FOREIGN    ACIDS.       227 


CHAPTER  XX. 

EXAMINATION    OF  VINEGAR    AS    TO    THE    PRESENCE    OF    FOREIGN 
ACIDS  AND  OF  METALS,  AS  WELL  AS  TO  ITS  DERIVATION. 

Detection  of  Acids. — Some  unscrupulous  manufacturers,  in 
order  to  pass  off  weak  or  inferior  vinegars,  adulterate  them 
with  mineral  acids.  Such  adulteration  is  not  only  a  fraud, 
but  dangerous  to  health,  and  it  is  necessary  to  indicate  the 
means  by  which  such  additions  can  be  detected. 

Sulphuric  Acid. — Add  to  a  sample  of  the  vinegar  a  few  drops 
of  a  solution  of  barium  chloride.  If  the  vinegar  becomes 
slightly  cloudy,  the  impurities  are  due  to  sulphates  naturally 
present  in  the  water  or  in  the  substances  from  which  the 
vinegar  has  been  made.  A  heavy  white  cloud  slow  in  subsid- 
ing will  indicate  free  sulphuric  acid  in  small  proportion.  If 
the  quantity  of  sulphuric  acid  is  more  than  a  thousandth,  the 
sulphate  of  baryta  produces  a  precipitate  and  falls  rapidly  to 
the  bottom  of  the  test-glass. 

The  presence  of  free  sulphuric  acid  in  vinegar  can  also  be 
determined  by  coating  a  porcelain  plate  with  strong  sugar 
solution  and  allowing  the  latter  to  dry  up.  By  bringing  a  few 
drops  of  the  vinegar  to  be  examined  upon  the  plate  and  placing 
the  latter  in  a  moderately  warm  place,  pure  vinegar  evapo- 
rates, leaving  a  slightly  brownish  stain  ;  vinegar  containing 
free  sulphuric  acid  leaves  a  dark-brown  stain  which  on  heating 
the  plate  turns  black. 

The  presence  of  free  sulphuric  acid  in  vinegar  can  be  deter- 
mined with  still  greater  sharpness  by  the  following  test :  Divide 
a  piece  of  starch  the  size  of  a  grain  of  wheat  in  50  cubic  centi- 
meters of  vinegar  arid  reduce  the  fluid  one-half  by  boiling.  To 
the  clear  fluid  cooled  to  the  ordinary  temperature  add  a  drop 
of  a  solution  of  iodine  in  spirits  of  wine.  Vinegar  containing 
no  free  sulphuric  acid  at  once  acquires  a  blue  coloration ;  if 
free  sulphuric  acid  be  present,  the  fluid  remains  colorless. 


228  MANUFACTURE  OF  VINEGAR. 

This  test  is  based  upon  the  fact  that  starch  by  continued  boil- 
ing with  sulphuric  acid  is  converted  into  dextrin  and  finally 
sugar.  Neither  of  these  bodies  reacts  upon  iodine,  while  a 
very  small  quantity  of  starch  gives  with  iodine  the  charac- 
teristic blue  coloration. 

Hydrochloric  Acid. — Take  about  100  cubic  centimeters  of 
the  vinegar  to  be  tested  and  distil  off  one-half  by  means  of  the 
apparatus  Fig.  50,  p.  216.  Compound  the  fluid  distilled  off 
with  a  few  drops  of  solution  of  nitrate  of  silver.  In  the  pres- 
ence of  hydrochloric  acid  a  white,  caseous  precipitate  is 
immediately  formed,  which  consists  of  chloride  of  silver  and 
dissolves  in  liquid  ammonia  added  in  excess. 

Nitric  acid  is  not  a  frequent  adulteration.  It  is  detected 
by  saturating  with  carbonate  of  sodium  or  of  potassium 
several  ounces  of  vinegar,  and  evaporating  the  whole  to  dry- 
ness.  The  addition  of  sulphuric  acid  and  copper  turnings 
will  cause  the  evolution  of  nitrous  vapors  if  nitric  acid  be 
present. 

Lactic  Acid. — In  many  varieties  of  vinegar  small  quantities 
of  lactic  acid  occur,  which  can  be  detected  by  slowly  evaporat- 
ing 100  cubic  centimeters  of  vinegar  in  a  porcelain  dish  until 
but  a  few  drops  remain.  If  these  drops  show  a  very  strong 
pure  acid  taste,  the  vinegar  examined  contains  lactic  acid.  The 
presence  of  lactic  acid  is,  however,  not  due  to  an  intentional 
addition,  but  to  the  material  used  in  the  manufacture  of  the 
vinegar,  that  prepared  from  grain,  malt  or  beer  always 
containing  it. 

Sulphurous  Acid. — This  acid  occurs  only  in  vinegar  pre- 
pared by  fermentation  when  stored  in  freshly  sulphured  bar- 
rels. It  may,  however,  occur  in  vinegar  whose  content  of 
acetic  acid  has  been  increased  by  the  addition  of  high-grade 
acetic  acid  prepared  from  wood-vinegar.  The  most  simple 
method  of  detecting  the  presence  of  sulphurous  acid  is  by 
placing  100  cubic  centimeters  of  the  vinegar  to  be  examined 
in  a  glass  distilling  apparatus,  and  connecting  the  latter  by  a 
glass-tube  with  a  vessel  containing  50  cubic  centimeters  of 


EXAMINATION    AS    TO    PRESENCE    OF    FOREIGN    ACIDS.       229 

pure  water  compounded  with  about  10  drops  of  nitric  acid. 
After  distilling  over  -jfc  of  the  vinegar  the  acidulated  water  is 
heated  to  boiling  for  a  few  minutes  and  solution  of  barium 
chloride  added.  If  the  vinegar  contains  sulphurous  acid,  a 
heavy  white  precipitate  is  formed. 

Detection  of  Metals. — The  occurrence  of  metals  in  vinegar  is 
due  to  the  vessels  employed  in  the  manufacture  or  the  storage, 
and,  hence,  the  use  of  metallic  utensils,  such  as  stop-cocks, 
pumps,  etc.,  should  be  avoided  as  much  as  possible.  Besides 
iron,  other  metals  such  as  copper,  zinc  and  tin  are  occasionally 
found  in  vinegar.  y  - 

Iron. — The  presence  of  this  metal  imparts  a  black  color  to 
the  vinegar,  which  is  increased  by  a  few  drops  of  tincture  of 
gall-nuts.  If  the  color  of  vinegar  compounded  with  a  few 
drops  of  solution  of  tannin  is  not  changed  after  standing  a  few 
hours,  the  vinegar  contains  no  iron,  or  only  so  small  a  quan- 
tity as  to  be  of  no  importance. 

Copper. — While  the  presence  of  a  small  quantity  of  iron  is  of 
little  importance  in  hygienic  respect,  that  of  copper,  zinc,  or 
tin  is  more  serious,  the  combinations  of  these  metals  having  a 
poisonous  effect  upon  the  organism.  Copper  in  vinegar  can 
be  detected  by  evaporating  to  dryness  about  1  quart  of  the 
vinegar  to  be  examined  and  dissolving  the  residue  in  a  few 
drops  of  nitric  acid.  By  compounding  a  portion  of  this  solu- 
tion with  ammonia  in  excess,  the  fluid  acquires  a  perceptible 
blue  coloration  in  .the  presence  of  copper.  The  latter  can  be 
shown  with  still  greater  sharpness  by  dipping  polished  iron 
into  another  portion  of  the  fluid.  If  the  iron  becomes  coated 
with  a  perceptible  red  film  (consisting  of  actual  copper),  the 
presence  of  this  metal  is  shown. 

Tin — Evaporate  to  dryness  at  least  2  or  3  quarts  of  the 
vinegar  ;  dissolve  the  residue  in  hydrochloric  acid,  and  con- 
duct sulphuretted  hydrogen  through  it  until  the  fluid  has 
acquired  a  strong  odor  of  the  latter.  If  a  precipitate  is  formed, 
it  is  filtered  off,  dissolved  in  strong  hydrochloric  acid,  and  the 
solution  divided  into  several  portions.  Compound  one  of  these 


230  MANUFACTURE    OF    VINEGAR. 

portions  with  dilute  solution  of  chloride  of  gold  ;  if  after  some 
time  it  becomes  red  and  precipitates  red  flakes,  the  vinegar 
contains  tin.  The  presence  of  tin  is  also  indicated  if  another 
portion  of  the  solution  of  the  precipitate  in  hydrochloric  acid 
does  not  acquire  a  blue  color  after  the  addition  of  potassium 
ferrocyanide.  The  behavior  of  the  fluid  towards  solution  of 
potassium  permanganate  may  serve  as  a  controlling  test ;  if 
the  fluid  contains  tin,  the  solution  of  potassium  permanganate 
becomes  discolored. 

Determination  of  the  Derivation  of  a  Vinegar. — The  examina- 
tion of  a  vinegar  as  regards  the  materials  used  in  its  prepara- 
tion is  generally  effected  by  the-  senses  of  odor  and  taste. 
There  are,  however,  a  number  of  tests  of  ready  execution  which 
assist  the  judgment  of  the  tongue  and  nose. 

Vinegar  prepared  from  dilute  spirits  of  wine  is  colorless  or 
only  colored  slightly  yellowish.  If  such  vinegar  has  a  dark 
yellow  color  resembling  that  of  wine,  it  is  generally  due  to  the 
addition  of  caramel,  the  addition  being  chiefly  made  on  ac- 
count of  the  erroneous  opinion  prevailing  among  the  public 
that  vinegar  clear  as  water  or  only  slightly  colored  lacks 
strength. 

Vinegar  prepared  from  spirits  of  wine,  when  carefully  evap- 
orated in  a  porcelain  dish,  leaves  a  very  small  residue  of  a 
whitish  or  very  slightly  yellow  color,  which  chiefly  consists  of 
the  salts  contained  in  the  water  used  for  the  preparation  of  the 
alcoholic  liquid,  an  accurate  examination  showing  it  to  consist 
of  calcium  acetate,  gypsum,  and  a  very  small  quantity  of 
sodium  chloride.  If  the  residue  is  of  a  dark  brown  color, 
swells  up  when  heated,  and  leaves  a  lustrous  black  coal,  the 
vinegar  has  been  colored  with  caramel. 

Beer  and  malt  vinegars  are  dark  yellow,  generally  with  a 
reddish  shade.  On  account  of  their  content  of  dextrin  they 
foam  when  shaken,  and,  when  carefully  evaporated,  leave  a 
brown,  gum-like  residue.  The  latter  consists  chiefly  of  dex- 
trin, and  contains,  besides  the  other  extractive  substances 
occurring  in  beer  and  malt  vinegar,  such  as  salts  of  ashes, 


EXAMINATION    AS    TO    PRESENCE    OF    FOREIGN    ACIDS.       231 

especially  much  phosphoric  acid.  On  heating  strongly  an 
odor  calling  to  mind  that  of  toasted  bread  is  evolved.  At  a 
still  higher  temperature  the  residue  turns  black  and  finally  acts 
like  caramel ;  it  evolves  pungent  vapors  and  leaves  a  lustrous 
coal. 

The  great  content  of  phosphoric  acid  characteristic  of  malt 
or  beer-vinegar  may  also  serve  for  the  determination  of  the 
derivation  of  such  vinegar.  By  compounding  beer  or  malt- 
vinegar  with  some  nitric  acid  and  a  solution  of  ammonium 
molybdate  and  heating,  the  fluid,  after  standing,  separates  a 
yellow  precipitate,  which  contains  the  phosphoric  acid  present 
in  the  fluid. 

Wine-vinegar  is  best  recognized  by  its  characteristic  odor, 
the  latter  becoming  especially  perceptible  by  rinsing  out  a 
large  tumbler  with  the  vinegar,  and  after  allowing  it  to  stand 
for  a  few  hours  examining  the  odor  of  the  few  drops  remaining 
in  the  tumbler.  The  greater  portion  of  the  acetic  acid  having 
then  volatilized,  the  vinous  odor  becomes  more  prominent. 
Cider-vinegar,  the  odor  of  which  is  somewhat  similar  to  that  of 
wine-vinegar,  can  in  this  manner  be  plainly  distinguished  from 
the  latter,  the  residue  in  the  tumbler  having  an  entirely  differ- 
ent odor. 

The  presence  of  potassium  bitartrate  is  a  characteristic  sign 
of  wine-vinegar.  By  evaporating  wine-vinegar  to  a  brownish 
syrupy  mass,  boiling  the  latter  with  some  water,  rapidly  filter- 
ing the  boiling  fluid  into  a  test  tube,  and  adding  double  its 
volume  of  strong  spirits  of  wine,  a  sand-like  precipitate  falls  to 
the/  bottom  of  the  test-tube,  which  consists  of  very  small 
crystals  of  tartar.  This,  however,  does  not  prove  the  sample 
to  be  genuine  wine-vinegar,  tartar  also  being  contained  in  imi- 
tations. With  a  sufficiently  sharp  sense  of  smell  this  is,  how- 
ever the  surest  means  of  distinguishing  genuine  wine-viriegar 
from  a  spurious  article. 

In  case  the  derivation  of  a  vinegar  is  to  be  established  with 
absolute  certainty,  it  has  to  be  subjected  to  an  accurate  chem- 
ical analysis,  and  this  being  better  made  by  an  analytical 


232  MANUFACTURE  OF  VINEGAR. 

chemist,  only  a  few  hints  are  here  given  which  may  serve  as 
a  guide  for  such  analyses. 

In  vinegar  prepared  from  a  fermented  fluid  a  certain  quan- 
tity of  glycerin  and  succinic  acid  will,  as  a  rule,  be  present, 
these  bodies  being  always  formed  by  the  fermentation  of  a  sac- 
chariferous  fluid,  and  consequently  when  found  the  vinegar  in 
question  cannot  have  been  prepared  from  an  alcoholic  liquid 
consisting  only  of  spirits  of  wine  and  water.  If  they  are  found 
only  in  very  small  quantities,  the  alcoholic  liquid  used  for  the 
production  of  the  vinegar  consists  very  likely  of  spirits  of  wine 
and  water  with  the  addition  of  beer  or  fermented  whiskey- 
mash,  and  in  this  case  small  quantities  of  dextrin  and  of  phos- 
phates will  also  be  found.  The  total  absence  of  tartaric  acid 
and  the  presence  of  malic  acid  indicate  the  derivation  of  the 
vinegar  under  examination  from  fruit,  though  not  necessarily 
from  apples  or  pears,  other  sacchariferous  fruits  also  containing 
malic  acid.  A  content  of  tartaric  acid  is,  however,  no  proof  of 
genuine  wine-vinegar,  as  its  presence  may  be  due  to  an  inten- 
tional addition,  and  it  is  very  difficult  to  arrive  at  a  certain 
conclusion  as  to  the  genuineness  of  a  pretended  wine-vinegar, 
especially  in  the  case  of  cider-vinegar  to  which  tartaric  acid 
has  been  added. 

Should  pepper,  chillies,  etc.,  be  added  to  vinegar  for  the 
purpose  of  conferring  more  pungency,  they  may  be  detected 
by  neutralizing  the  acid  with  carbonate  of  soda  and  tasting 
the  liquor;  if  these  bodies  be  present,  the  solution  will  still 
retain  the  sharpness  peculiar  to  such  spices. 


WOOD    VINEGAR    AND    OTHER,    BY-PRODUCTS. 


233 


CHAPTER  XXL 


WOOD    VINEGAR    AND    OTHER    BY-PRODUCTS    OBTAINED    IN    THE 
DESTRUCTIVE    DISTILLATION    OF    WOOD. 

Constitution  of  Wood. — Wood  essentially  consists  of  woody 
fiber,  small  quantities  of  salts  and  sap  and  a  varying  quantity 
of  hygroscopic  water.  Woody  fiber  or  cellulose  constitutes 
about  96  per  cent,  of  dry  wood,  and  is  composed  of  C6H1005 ; 
100  parts  containing  44.45  parts  carbon,  6.17  hydrogen  and 
49.38  oxygen.  The  vegetable  sap  consists  chiefly  of  water, 
but  contains  organic  as  well  as  inorganic  matters,  partly  in 
solution  and  partly  in  suspension.  The  inorganic  constituents 
— the  ash  left  after  the  incineration  of  the  wood — are  the  same 
in  all  kinds  of  wood.  The  quantity  of  water  in  wood  is  gen- 
erally larger  in  the  soft  than  in  the  hard  varieties.  One  hun- 
dred parts  of  wood  recently  felled  contain,  according  to 
Schubler  and  Neuffler,  the  following  quanties  of  water : 


Beech 18.6 

Birch 30.8 

Oak 34.7 

Oak  (quercus  pedunculata)  .  35.4 
White  fir.  .  37.1 


Common  fir 39.7 

Red  Beech 39.7 

Alder  ...  41.6 

Elm 44.5 

Ked  fir.  .  45.2 


The  branches  always  contain  more  water  than  the  trunk. 

Wood  is  called  air-dry  when  its  weight  no  longer  changes 
at  an  ordinary  temperature  ;  in  this  state  it  contains  still  17  to 
20  per  cent,  of  water.  The  latter  can  be  expelled  by  con- 
tinued heating  at  212°  F.,  but  wood  thus  dried  re-absorbs 
about  20  per  c'ent.  of  water  from  the  air. 

When  felled,  nearly  all  kinds  of  wood  are  specifically  lighter 
than  water.  A  few  varieties  are  heavier,  but  these  are  the 
harder  kinds  in  which  the  cellulose  is  so  compactly  packed  as 
to  leave  very  little  space  for  the  retention  of  air.  The  table 
here  given  exhibits  approximately  the  specific  gravity  of  the 
different  woods : 


234  MANUFACTURE    OF    VINEGAR. 


Larch     

.    .  .0.47 

Ash    .    .    . 

Fir  and  pine  .    . 

.    .  0.55 

Oak    .    .    . 

Beech     ..' 

.    .  0.59 

Hornbeam 

Birch  . 

062 

0.64 
0.70 
0.76 


The  content  of  ash  is  not  the  same  in  all  woods ;  it  varying 
considerably  in  different  parts  of  the  same  tree  and  also  with 
its  age.  According  to  Violet,  in  the  cherry  tree  the  content  of 
ash  is  greatest  in  the  leaves  (about  7  per  cent.),  next  in  the 
lower  parts  of  the  roots  (5  per  cent.) ;  considerably  greater  in 
the  bark  than  in  the  wood,  in  the  former  from  1.1  to  3.7 
per  cent.,  and  in  the  latter  0.1  to  0.3  per  cent.  Saussure 
found  in  the  bark  of  the  oak  6  per  cent.,  in  the  branches 
0.4  per  cent.,  and  in  the  trunk  0.2  per  cent,  of  ash.  The  ash 
consists  chiefly  of  carbonates  of  calcium,  potassium,  and  sodi- 
um, further  of  magnesia  and  the  phosphates  of  different  bases. 

The  average  composition  of  100  parts  of  air-dry  wood  is : 
Carbon  39.6  parts,  hydrogen  4.8,  oxygen  and  nitrogen  34.8, 
ash  0.8,  hygroscopic  water  20  ;  and  that  of  artificially  dried 
wood  :  Carbon  49.5,  hydrogen  6,  oxygen  and  nitrogen  43.5, 
ash  1. 

Decomposition  of  wood. — Cellulose  when  carefully  treated  re- 
mains unchanged  for  a  long  time,  even  thousands  of  years. 
Wood  is,  however,  subject  to  greater  changes,  though  under 
especially  favorable  circumstances  it  may  last  for  several  cen- 
turies. In  the  presence  of  sufficient  moisture  and  air  the  ni- 
trogenous .bodies  of  the  sap  are,  no  doubt,  first  decomposed, 
and  the  decomposition  being  next  transferred  to  the  woody 
fiber,  the  latter  loses  its  coherence,  becomes  gray,  then  brown, 
and  finally  decays.  Hence,  wood  rich  in  water  decays  more 
rapidly  than  dry  wood. 

Wood  to  be  preserved  should,  therefore,  be  as  dry  as  pos- 
sible, and  the  nitrogenous  bodies,  which  can  be  but  incom- 
pletely removed  by  lixiviation,  be  converted  into  insoluble 
combinations  ;  tar  and  one  of  its  most  .effective  constituents — 
creosote — mercuric  chloride,  blue  vitriol,  chloride  of  zinc,  and 
many  other  substances  having  been  recommended  for  this 


WOOD    VINEGAR    AND    OTHER    BY-PRODUCTS.  235 

purpose.  Moreover,  it  has  been  successfully  attempted  to 
produce  certain  insoluble  bodies,  such  as  aluminium  and  cop- 
per soaps,  in  the  interior  of  the  wood  by  saturating  it  with  soda 
soap  and  then  with  aluminium  chloride,  or  blue  vitriol,  or  such 
as  barium  phosphate,  by  saturating  with  sodium  phosphate 
and  then  with  barium  chloride,  etc. 

By  heating  to  212°  F.  wood  remains  unchanged,  it  yielding 
up  only  sap  constituents.  If,  however,  the  temperature  be  in- 
creased, for  instance  to  392°  F.,  a  small  quantity  of  sugar  is, 
according  to  Mulder,  formed  from  cellulose  in  a  closed  vessel, 
and  from"  wood,  according  to  G.  Williams,  an  acid  not  yet 
thoroughly  known,  methyl  alcohol  (see  further  on),  an  oil 
boiling  between  277°  and  421°  F.,  and  a  small  quantity  of 
furfurol. 

In  the  presence  of  water,  wood  in  a  closed  vessel  is,  however, 
already  decomposed  at  about  293°  F.  If  this  temperature  be 
kept  up  for  a  long  time,  for  instance,  a  month,  the  wood, 
according  to  Sorby,  is  converted  into  a  lustrous  black  mass 
with  the  formation  of  acetic  acid  and  gases. 

According  to  Daubree,  pine,  when  heated  for  some  time  with 
water  in  an  entirely  closed  vessel  to  752°  F.,  is  converted  into 
a  mass  having  the  appearance  of  stone-coal  and  approaching 
anthracite  in  its  behavior.  Baroulier  made  similar  observa- 
tions, masses  resembling  stone-coal  being  formed  by  pressing 
saw-dust,  stems  and  leaves  together  in  moist  clay  and  heating 
continuously  to  from  392°  to  572°  F.,  so  that  the  vapors  and 
gases  could  only  escape  very  slowly. 

By  avoiding  all  heating,  concentrated  sulphuric  acid  converts 
cellulose  into  a  gum-like  body — dextrin — which  by  diluting 
with  water  and  long  digesting  is  converted  into  sugar  (starch 
sugar).  When  heated,  the  wood,  however,  turns  black  and  is 
completely  destroyed,  sulphurous  acid  being  at  the  same  time 
evolved.  With  concentrated  sulphuric  acid,  cellulose  swells 
up  and  gradually  dissolves,  being  precipitated  by  water  in 
white  flocks.  The  starch-like  body  thus  obtained  is  called 
amyloid.  It  is  an  altered  cellulose  and  is  colored  blue  by 


236  MANUFACTURE    OF    VINEGAR. 

iodine.  At  the  ordinary  temperature,  wood  is  but  little 
affected  by  dilute  sulphuric  aci.d,  while  at  a  higher  tempera- 
ture a  certain  quantity  of  sugar — glucose  or  dextrose — is 
formed,  water  being,  absorbed  at  the  same  time.  This  be- 
havior has  been  utilized  for  obtaining  alcohol  by  fermenting 
the  sugar  .thus  obtained  with  yeast  after  neutralizing  the  acid 
by  calcium  carbonate,  for  instance,  chalk.  The  woody  fiber 
remaining  unattacked  can  be  used  as  material  for  paper. 

Concentrated  hydrochloric  acid  colors  wood  rose  color  to 
violet-red  and  rapidly  destroys  it.  Dilute  hydrochloric  acid 
on  heating,  forms  sugar  ;  but,  according  to  Zetterlund,  the 
quantity  of  absolute  alcohol  obtainable  in  this  manner  is  very 
small,  amounting  to  about  2.3  per  cent,  of  the  weight  of  the 
wood.*  By  macerating  wood  with  dilute  hydrochloric  acid  at 
an  ordinary  temperature,  the  cellulose  is  not  changed,  but  the 
so-called  lignin  seems  to  be  dissolved.  By  forcing  dilute  hy- 
drochloric acid  by  a  pressure  of  two  atmospheres  into  trunks 
provided  with  the  bark,  and  subsequent  washing  out  in  the 
same  manner  with  water,  and  drying  by  means  of  a  current  of 
air  at  98.6°  F.,  wood  acquires  great  plasticity.  In  a  moist 
state  wood  thus  treated  can  be  pressed  together  to  one-tenth  of 
its  original  volume. 

Hydriodic  acid  reduces  wood  to  various  hydrocarbons,  water 
being  formed  and  iodine  liberated. 

Concentrated  nitric  acid,  or,  still  better,  a  mixture  of  it  and 
sulphuric  acid,  converts  cellulose,  for  instance,  cotton,  into 
gun-cotton,  while  wood  is  colored  yellow  and  partially  dis- 
solved. Dilute  nitric  acid,  for  instance,  of  1.20  specific  gravity, 
has  no  effect  in  the  cold,  and  but  little  when  heated. 

By  bringing  cellulose  in  contact  with  dilute  aqueous  solu- 
tions of  alkalies,  it  is  colored  blue  by  iodine,  and  consequently 
a  starch-like  substance  is  formed,  but  no  humus-like  bodies  ; 

*  According  to  prior  experiments  by  Bachet,  it  is,  however,  claimed  that  up  ta 
23  per  cent,  of  sugar  can  be  obtained  from  wood%by  boiling  10  to  12  hours  with 
water  containing  one-tenth  of  hydrochloric  acid. 


WOOD    VINEGAR    AND    OTHER    BY-PRODUCTS.  237 

from  wood  only  the  lignin  is  extracted,  the  woody  fibre  remain- 
ing unchanged.  By  heating  with  strong  alkaline  lyes,  or,  still 
better,  by  fusing  with  solid  caustic  alkalies,  acetic  acid  is,  ac- 
cording to  Braconnot,  first  formed  and  then  oxalic  acid.  The 
latter  acid  is  frequently  obtained  by  this  process. 

On  heating  shavings  with  sodium  sulphide  an  abundant 
quantity  of  acetic  acid  (sodium  acetate)  is  formed,  the  addition 
of  sulphur  to  caustic  soda  apparently  having  the  effect  of  pre- 
venting the  formation  of  oxalic  acid. 

Products  of  Destructive  Distillation, — Besides  charcoal,  there 
are  formed  in  the  decomposition  of  wood  under  exclusion  of 
air,  a  great  number  of  products,  the  kind  and  quantity  of 
which  depend  on  the  temperature  to  which  the  wood  has  been 
exposed,  as  well  as  on  whether  that  temperature  has  been  slow- 
ly raised  to  a  certain  point,  or  as  rapidly  as  possible. 

The  products  obtained  by  gradually  increasing  the  heat  are, 
at  the  ordinary  temperature,  either  gaseous,  liquid  or  solid. 
In  speaking  of  the  gases,  which  will  be  first  considered,  a  dis- 
tinction has  to  be  made  between  those  which  must  be  accepted 
as  actual  products  of  decomposition  of  wood,  and  those  which 
are  formed  by  certain  volatile  fluids  which  are  liquid  at  the 
ordinary  temperature,  but  at  higher  degrees  of  heat  suffer  de- 
composition and  yield  gaseous  products. 

Gaseous  products  of  distillation. — At  the  commencement  of 
decomposition,  between  320°  and  374°  F.,  carbonic  acid,  CO2, 
mixed  only  with  very  small  quantities  of  carbonic  oxide,  CO, 
is  chiefly  found,  the  quantity  of  the  latter  increasing  with  the 
rise  in  the  temperature.  At  between  392°  and  428°  F.  the 
quantities  of  carbonic  acid  and  carbonic  oxide  are  nearly  equal, 
and  small  quantities  of  methane  or  marsh  gas,  CH4,  appear. 
At  between  608°  and  680°  F.,  carbonic  acid  and  carbonic 
oxide  become  less  prominent,  and  methane  appears  in  larger 
quantities.  Above  this  temperature  the  content  of  carbonic 
acid  in  the  gas  mixture  becomes  small,  while  that  of  methane, 
mixed  also  with  hydrogen,  increases,  and  heavier  hydro- 
carbons make  their  appearance. 


238  MANUFACTURE    OF    VINEGAR. 

By  igniting  the  gases  escaping  from  the  distilling  apparatus, 
a  conclusion  can  be  drawn  from  the  appearance  of  the  flame 
as  to  the  kind  of  products  which  are  developing.  At  first 
the  flame  is  slightly  luminous  and  shows  the  characteristic- 
pale  blue  color  of  the  carbonic  acid  flame.  Later  on,  in  con- 
sequence of  the  increase  in  the  formation  of  methane  and 
heavier  hydrocarbons,  the  flame  exhibits  periodically  a  pure 
white  color,  while  the  blue  coloration  gradually  becomes  less 
prominent,  until  finally  the  gases  burn  with  the  luminous 
pure  white  flame  of  heavy  hydrocarbons. 

The  following  table  shows  the  order  in  which  the  gaseous 
combinations  are  formed  at  different  temperatures : 

Temperature.  Name.  Composition. 

{Carbonic  acid  CO2  ] 

Carbonic  oxide          CO 

'55:        , 

Ethy'lene  C2H,  lre' 


From    680°    to   812°   F. 


Propylene 


(above  this  temperature  ]   Butylene  C4H8 

only  a  very  small  quan-   |   Benzene  C6H6  ~) 


tity  of  gas  is  evolved). 


Toluene  (-7^8  I    Liquid  at  the  or- 

Xylene  C8H]0  }•      dinary    temper- 

Cumene  C9H12  |       ture. 

Napthalene  C]0H8 


Pettenkofer  found  the  composition  of  wood  gases  as  follows  : 

Carbonic  Carbonic  Heavy 

Air.       acid.       oxide.     Methane.  Hydrogen,     hydrocarbons. 
Up  to  680°  F.    .    .    5        54.5        38.8            6.6 

Above  680°  F.  .    .    0        18-25      40-50          8-12  14-17                  6.7 

The  process  by  which  the  above-mentioned  bodies,  of  which 
the  products  of  benzene  caught  by  cooling  may  also  be  vola- 
tilized, are  formed  is  of  a  very  complicated  nature,  and  while 
as  regards  the  formation  of  many  of  these  bodies  only  hypoth- 
eses can  be  advanced,  that  of  others  is  readily  explained. 

Before  entering  upon  this  explanation,  it  is  well  to  remem- 
ber that  in  the  execution  of  carbonization  and  destructive  dis- 
tillation on  a  large  scale,  it  is  impossible  to  maintain  the  same 


WOOD    VINEGAR    AND    OTHER    BY-PRODUCTS.  239 

temperature  in  all  parts  of  the  apparatus,  and  that  consider- 
able differences  in  temperature  will  occur.  Furthermore  cer- 
tain volatile  bodies  when  highly  heated,  i.  e.,  in  contact  with 
hot  places  of  the  distilling  apparatus,  possess  the  property  of 
undergoing  decomposition,  new  combinations  being  formed. 
This  explains  the  origin  of  many  bodies  which  appear  among 
the  products  of  the  decomposition  of  wood. 

When  wood  substance  is  heated,  its  elementary  constituents 
act  at  first  upon  each  other  in  such  a  manner  that  water  is 
formed,  and  consequently  steam  is  evolved,  when  the  wood, 
after  being  freed  from  all  moisture,  is  heated  to  320°  F. 
However,  at  a  higher  temperature  the  affinity  of  carbon  for 
oxygen  and  hydrogen  asserts  itself,  and  at  first  combinations 
composed  of  the  three  constituents  of  wood  are  formed. 

At  a  certain  temperature  the  affinity  of  carbon  for  oxygen 
becomes  so  potent  that  the  two  bodies  enter  into  combina- 
tion, and  carbonic  acid — the  combination  of  carbon  richest  in 
oxygen — is  formed  so  long  as  an  abundance  of  oxygen  is 
present.  At  a  later  stage  of  decomposition,  when  the  quan- 
tity of  oxygen  in  the  mass  has  decreased  and  the  temperature 
has  become  higher,  carbonic  oxide — the  combination  of  car- 
bon poorer  in  oxygen — appears  in  larger  quantity.  It  is  due 
to  the  affinity  of  hydrogen  for  carbon  that  two  hydrocarbons 
are  formed.  So  long  as  hydrogen  is  present  in  abundance, 
methane  CH4 — a  combination  of  carbon  with  hydrogen  com- 
pletely saturated  with  hydrogen — is  first  formed,  and  then,  at 
a  somewhat  higher  temperature,  ethylene  C2H4,a  combination 
poorer  in  hydrogen. 

The  gases  above  mentioned,  namely  :  Carbonic  acid,  carbonic 
oxide,  methane  and  ethylene,  are  very  possibly  those  combi- 
nations which  may  originate  directly  from  the  decomposition 
of  the  wood  substance.  When  these  gases  are  brought  in 
contact  with  glowing  coal,  or  are  highly  heated — two  cases 
which  always  occur  in  destructive  distillation — they  suffer 
decomposition,  and  new  bodies  appear  in  the  products  of 
distillation. 


240  MANUFACTURE    OF    VINEGAR. 

Carbonic  acid  in  contact  with  glowing  coal  changes  to  car- 
bonic oxide,  C02-|-C=2CO,  and  it  is  very  likely  that  the  con- 
stant increase  of  the  content  of  carbonic  oxide  in  the  gases 
with  an  increasing  temperature,  is  partly  due  to  this  reciprocal 
action. 

Hydrogen  appears  only  when  the  temperature  has  reached 
a  point  at  which  methane  and  ethylene  are  formed  in  abun- 
dance, the  hydrogen  being  split  off  from  these  combinations. 
So  long  as  the  temperature  is  not  much  above  750°  F.,  acety- 
lene, C2H2,  and  hydrogen  are  chiefly  formed  from  methane, 
while  at  a  red  heat,  methane  is  directly  decomposed  to  its 
elementary  constituents. 

Hence  at  lower  degrees  of  heat  is  formed  : 

2CH4  =  C2H2     -I-     H6 

methane  =  acetylene  +  hydrogen. 

and  at  higher  degrees  of  heat :  CH4  =  C  +  H4. 

On  the  portions  of  the  iron  distilling  vessels,  which  are 
highly  heated  in  the  distillation  of  wood,  a  graphite-like  layer  of 
carbon  is  found  which  adheres  quite  firmly  and  is  very  likely 
formed  by  the  decomposition  of  methane  and  other  hydrocar- 
bons in  coming  in  contact  with  the  hot  surface,  carbon  being 
thereby  separated. 

Ethylene  C2H4  is  decomposed  at  a  comparatively  low  tem- 
perature to  acetylene  and  methane. 

3  C2H4  =  2  C2H2  +  2  CH4 
ethylene  =  acetylene  +  methane. 

At  a  higher  temperature,  ethylene  is  decomposed  so  that  the 
above  mentioned  products  are  formed,  carbon,  however  being 
at  the  same  time  separated. 

4  C'H4  =  2  C2H2  -1-  3  CH4  -f  C. 

The  above-mentioned  decompositions  of  methane,  however, 
are  not  the  only  ones  which  may  occur,  and  according  to  the 
temperature,  there  may  be  formed  from  these  gases  a  series  of 


WOOD    VINEGAR    AND    OTHER    BY-PRODUCTS.  241 

other  combinations.  The  appearance  of  propylene  may,  for 
instance,  be  explained  by  the  reciprocal  action  of  methane  and 
carbonic  oxide. 

2  CH4  +          CO          =    C3T76    -J-  H2O 

methane  +  carbonic  oxide  =  propylene  +  water. 

Besides  the  processes  of  decomposition  above  represented, 
there  are  others  which  are  a  source  of  the  formation  of  gaseous 
bodies.  At  a  temperature  of  between  392°  and  536°  F.  a  con- 
siderable quantity  of  acetic  acid  and  methyl  alcohol  is  already 
formed,  and  the  vapors  of  this  combination  are  entirely  or  par- 
tially decomposed  when  highly  heated,  and  this  explains  why 
in  heating  the  wood  very  rapidly,  very  little  acetic  acid  and 
methyl  alcohol  are  formed,  but,  on  the  other  hand,  a  very  large 
quantity  of  gaseous  and  tar  products. 

Wood  contains  in  its  sap  constituents  small  quantities  of 
nitrogenous  combinations  and  the  nitrogen  forms  with  hydro- 
gen, ammonia,  which,  on  coming  together  with  hydrocarbons, 
forms  at  once  substitution  products,  of  which,  for  instance, 
methylamir.e,  in  which  a  portion  of  the  hydrogen  in  the  am- 
monia is  replaced  by  methyl,  appears  in  proportionally  largest 
quantity. 

CH40  +     IT3N  CH5N     -f  H20 

methyl  alcohol  +  ammonia  =  methylamine  +  water. 

Since  in  the  destructive  distillation  of  wood  a  large  quantity 
of  gases  is  evolved,  the  apparatuses  in  which  the  products  of 
distillation,  liquid  at  the  ordinary  temperature,  are  to  be  con- 
densed must  be  quite- large,  as  otherwise  the  seams  might  open 
in  consequence  of  the  pressure  of  the  gases ;  or  at  least  a  large 
quantity  of  bodies  which  might  be  condensed  would  be  carried 
away  by  the  powerful  current  of  gases. 

By  destructive  distillation  100  kilogrammes  of  wood  yield 
on  an  average  24.97  cubic  meters  of  gas.  This  quantity,  how- 
ever, corresponds  only  to  the  conditions  prevailing  when  dis- 
tillation is  carried  on  slowly.  When  the  heat  is  rapidly  raised 
'  16 


242  MANUFACTURE    OP    VINEGAR. 

nearly  50  per  cent,  more  of  gas  is  obtained  and  of  course  the 
yield  of  liquid  products  of  distillation  and  of  charcoal  is  cor- 
respondingly reduced.  F.  Fischer  made  thorough  investiga- 
tions regarding  the  gases  formed  in  the  destructive  distillation 
of  wood.  He  found  that  the  average  yield  from  100  parts  of 
beech  is  45  kilogrammes  wood  vinegar  (with  4  kilogrammes 
acetic  anhydride  and  1.1  kilogramme  wood  spirit),  23  kilo- 
grammes charcoal,  4  kilogrammes  tar,  28  kilogrammes  gases 
and  steam. 

Liquid  Products  of  Distillation. — The  products  of  destructive 
distillation  of  wood  which  can  be  condensed  by  cooling,  sepa- 
rate, when  at  rest,  into  two  layers,  the  upper  lighter  one,  which 
is  of  an  acid  nature,  forming  the  wood  vinegar,  while  the  lower, 
denser  one,  is  termed  tar.  Since  these  fluids  are  formed  at 
temperatures  widely  apart  and  there  is  considerable  difference 
in  the  chemical  constitution  of  the  bodies  contained  in  them, 
it  is  best  to  consider  them  separately. 

Wood  Vinegar. — At  the  lowest  temperature  at  which  the  de- 
composition of  wood  commences — according  to  Violette  be- 
tween 302°  and  312°  F.,  and  according  to  Gillot,  even  be- 
tween 216.6°  and  244.4°  F. — the  three  elementary  constituents 
of  wood  act  upon  each  other,  and,  besides  a  number  of  acids 
of  the  fatty  acid  series  and  methyl  alcohol,  there  are  formed 
certain  products  of  the  decomposition  of  these  bodies.  The 
formation  of  fatty  acids,  amongst  which  acetic  acid  appears  in 
largest  quantity,  commences,  according  to  Gillot,  at  255°  F., 
and  reaches  its  maximum  at  437°  F.  At  higher  temperatures 
considerable  quantities  of  products  of  decomposition  of  the 
fatty  acids  appear,  so  that,  according  to  the  temperature  and 
duration  of  distillation,  there  may  be  considerable  variation,  as 
regards  the  quantities  of  bodies  contained  in  it,  in  the  composi- 
tion of  wood  vinegar  gained  on  a  large  scale.  The  presence  of 
the  following  fatty  acids  in  wood  vinegar  has  been  definitely 
established : 


WOOD    VINEGAR    AND    OTHER    BY-PRODUCTS.  243 

Formic  acid '  . CH2O2 

Acetic  acid C2H4O2 

Propionic  acid C3H6O2 

Butyric  acid C4H8O2 

Valeric  acid  '. C5H]0O2 

Caproicacid C6Hi2O2 

Formic  acid  boils  at  212°  F.,  and  since  the  boiling-point  of 
the  succeeding  members  of  this  series  of  acids  lies  about  68° 
higher,  it  may  be  supposed  that  the  lower  members  of  this 
series  of  acids  are  found  in  the  portion  of  the  wood-vinegar 
which  distils  over  at  a  comparatively  low  temperature.  This 
has  been  fully  confirmed  by  experience,  and  for  this  reason  the 
wood  should  be  very  slowly  heated  if  the  largest  possible  yield 
of  acetic  acid  is  to  be  obtained. 

Methyl  alcohol,  CH4O,  may  be  produced  from  marsh -gas  by 
subjecting  that  compound  to  the  action  of  chlorine  in  sunshine, 
whereby  chloromethane,  or  methyl  chloride,  CH3C1,  is  pro- 
duced, and  then  distilling  with  potash.  In  the  destructive 
distillation  of  wood  it  is  very  likely  formed  by  the  action  of 
carbonic  acid  upon  methane : 

CH4   +        CO2  CH40      +          CO 

methane  +  carbonic  acid  =  methyl  alcohol  +  carbonic  oxide, 

so  that  the  appearance  of  constantly  increasing  quantities  of 
carbonic  oxide  beside  carbonic  acid  would  appear  to  be  ex- 
plained by  this  process. 

Acetone,  C3H60,  is  formed  directly  from  acetic  acid  by  con- 
ducting the  vapors  of  the  latter  through  a  red-hot  tube  whereby 
carbonic  acid  and  water  are  formed  : 

2(C2H402)  =  C3H60  +         C02        +  B20 
acetic  acid    =  acetone  +  carbonic  acid  -f  water. 

It  may,  however,  be  also  formed  from  methyl  alcohol  and 
acetic  acid,  or  from  methyl  alcohol  and  carbonic  oxide.  The 
occurrence  of  methyl  acetic  ether,  CH3,C2H302,  in  wood  vine- 
gar is  due  to  acetic  acid  and  methyl  alcohol  in  a  nascent  state 
acting  upon  each  other,  while  the  presence  of  aldehyde, 


244  MANUFACTURE    OP    VINEGAR. 

C4H1002,  may  be  explained  by  tbe  reciprocal  action  of  methyl 
alcohol  and  acetic  acid,  two  molecules  of  methyl  alcohol  with 
one  molecule  of  acetic  acid  being  transformed  to  dimethyl 
acetal  (=  aldehyde)  while  water  and  oxygen  are  liberated,  the 
latter  being  immediately  fixed  by  other  products. 

2(CIT40)     +C2H402      =  C4H100,  +  H,0   +      O 

methyl  alcohol  +  acetic  acid  =  aldehyde  -f  water  +  oxygen. 

Further  products  of  the  reciprocal  action  of  the  fatty  acids, 
methane  and  carbonic  oxide,  are:  Metacetone,  C6H100,  and 
allyl  alcohol  or  furfurol,  C3H60.  The  small  quantities  of 
nitrogen  originating  from  the  sap  constituents  of  the  wood, 
which  are  present  in  destructive  distillation,  appear  in  the 
form  of  methylamine  C3H2N,  and  ammonia. 

There  is  such  a  variation  in  the  quantities  of  the  bodies  of 
which  wood  vinegar  is  composed  that  it  is  impossible  to  give 
figures  of  general  value  in  regard  to  them,  the  time  during 
which  heating  takes  place  being  of  great  influence  in  this  re- 
spect, so  that  from  the  same  variety  of  wood,  by  rapid  heating, 
only  a  few  tenths  of  the  quantity  of  products  are  frequently 
obtained,  which  would  result  by  slow  heating.  This  fact  is  of 
the  greatest  importance  for  the  practical  manufacture  of  wood 
vinegar  and  wood  spirit,  and  will  be  more  fully  discussed  later 
on.  It  may  here  only  be  mentioned  that  from  air  dry  wood, 
with  not  too  rapid  distillation,  30  to  53  per  cent,  (from  most 
varieties  of  wood  on  an  average  40  to  45  per  cent.)  of  wood 
vinegar  may  be  obtained,  the  specific  gravity  of  which  varies 
between  1.018  and  1.030,  and  which  contains  between  2.5  and 
'8.5  per  cent,  acetic  anhydride,  calculated  from  the  gravity  of 
the  wood  vinegar. 

Tar.  The  products  which  occur  in  wood  tar  are  still  more 
numerous  than  those  which  originate  during  the  period  in 
which  there  is  still  considerable  oxygen  in  the  heated  mass. 
Among  the  combinations  which  may  be  termed  tar  products 
in  the  actual  sense  of  the  word,  are  only  a  few  containing 
oxygen,  and  these  occur  only  in  smaller  quantities.  The 


WOOD    VINEGAR    AND    OTHER    BY-PRODUCTS.  245 

larger  quantity  of  the  tar  products  consist  of  hydrocarbon 
combinations  and  must  be  considered  as  having  been  formed 
by  the  elements,  carbon  and  hydrogen,  grouping  themselves 
in  various  ways  at  different  temperatures.  Ethylene  very 
likely  breaks  up  into  a  series  of  hydrocarbon  combinations,  at 
a  slightly  higher  temperature  than  that  at  which  it  originates, 
as  is,  for  instance,  shown  for  naphthalene 

ethylcne  =  naphthalene  +  methaner 
8(C2H4)  =      <J10H8      +G(CH4), 

and  the  formation  of  all  the  other  hydrocarbons  might  in  the 
same  manner  be  explained.  When  derived  from  hard  wood, 
wood-tar  consists  chiefly  of  parafins,*  toluene,  xylene,  cresol, 
guaiacol,  phenol,  and  methyl  derivatives  of  pyrogallol. 

Since  a  portion  of  these  combinations  is  already  formed  at  a 
temperature  at  which  acetic  acid  is  still  evolved  from  the  wood, 
certain  quantities  are  found  dissolved  in  wood  vinegar,  the  tar 
products  being  jointly  condensed  with  the  wood-vinegar. 
While,  according  to  Pettenkofer,  the  heavy  hydrocarbons  ap- 
pear only  at  a  temperature  of  above  680°  F.,  according  to  Gil- 
lot,  tar  in  abundance  is  already  formed  at  565°  F.  Practical 
experience,  however,  has  shown  that  the  largest  quantities  of 
tar  are  formed  only  at  a  higher  temperature,  and  the  boiling- 
points  of  tar  products  also  indicate  a  high  temperature  of  for- 
mation, naphthalene,  for  instance,  boiling  at  413.6°  F.  and 
paraffin  only  at  over  572°  F. 

Besides  the  above-mentioned  combinations,  various  chemists 
have  established  in  wood-tar  the  presence  of  a  long  series  of 
combinations,  but  up  to  the  present  time  they  have  not  been 
more  closely  examined,  or  they  appear  in  such  small  quantities 
that  their  occurrence  is  only  of  theoretical  interest.  In  this 
series  may  be  mentioned  :  Iridol/  citriol,  rubidol,  benzidol ; 
further,  retene,  pittacall,  cedriret,  and  pyroxanthogene ;  and 

*  Under  the  name  paraffin  are  very  likely  comprised  many  combinations  which, 
though  having  the  same  percentage  composition,  possess  different  physical  and 
chemical  properties,  i.  e.,  are  isomeric. 


246  MANUFACTURE    OP    VINEGAR. 

further,  the  combinations  established  by  Reich  enbach,  kapno- 
mar,  picamar,  creosote  and  xylite,  and  finally  mesite,  prepared 
by  Schweizer. 

The  yield  of  tar  obtained  in  the  destructive  distillation  of 
wood  depends  on  the  time  and  temperature  used,  but  also 
essentially  on  the  nature  of  the  wood  itself,  resinous  woods 
yielding  larger  quantities  of  tar  than  the  varieties  free  from 
rosin.  By  slow  distillation,  the  former  yield  9  to  14  per  cent., 
and  the  latter,  5  to  11  per  cent,  of  tar.  The  more  quickly  the 
process  of  distillation  is  conducted  the  greater  will  be  the  yield 
of  tar  and  gas,  while  that  of  acetic  acid  is  less.  The  table 
below  shows  the  bodies  appearing  in  the  destructive  distillation 
of  wood  and  the  limits  of  temperature  of  technical  importance, 
within  which  they  are  very  likely  formed : 

GASES.  WOOD  VINEGAR.  TAB. 

Carbonic  acid  .  )  Formic  acid )  Qt.AO  f^  KWO  TT  Benzene 1  ^  *i 

Carbonic  oxide  U20°  to  680°  F.  Acetic  acid j"  d<  0/z   * '  Toluene 

Methane j  Propionic  acid i  Xylene 

Hydrogen 1  Butyric  acid !  QQ.,o  +„  '«cno  i?  <  'umene 

Acetylene |  Valeric  acid f  °92   to  68°   F"  Naphthalene 

Ethylene }>6800  to  809.6°  F.Caproic  acid J  Paraffin 

Propylene |  Methyl  alcohol 392°  to  683°  F.  Phenol 

Butylene J  Acetone 1  Anisol . 


Metacetone .. . 
Acetic  acid  and 

methyl  ether 

Dimethyl  acetate 

Aldehyde  

Methylamine  acetate  J 


Phenetol  ....  j  r 


482°  to  680°  F. 


At  present  only  a  comparatively  small  number  of  the  pro- 
ducts originating  in  the  destructive  distillation  of  wood  are 
utilized.  Of  the  combinations  which  belong  to  the  series  of 
tar  bodies,  the  only  products  which  have  actually  found  indus- 
trial application,  are  creosote,  which  consists  chiefly  of  phenic 
acid,  and  the  light  and  heavy  oils  which  can  be  obtained  by 
distillation  from  the  tar. 

It  is,  however,  possible  to  separate  from  wood  tar  the  various 
combinations  contained  in  it,  as  has  been  successfully  done 
with  coal  tar.  Benzene,  toluene,  naphthalene,  etc.,  can  be  pre- 
pared, and  coloring  matters  manufactured  from  these  hydro- 
carbons. The  reason  why  this  is  not  done  is  very  likely  to  be 
sought  in  the  fact  that  in  the  manufacture  of  illuminating  gas 


WOOD    VINEGAR    AND    OTHER    BY-PRODUCTS.  247 

from  coal,  a  sufficiently  large  quantity  of  coal  tar  is  obtained 
to  supply  the  demand  of  the  manufacturers  of  coal  tar  colors. 
Paraffin  might  also  bs  obtained  from  wood  tar,  but  its  manu- 
facture would  not  pay  in  competition  with  the  article  obtained 
from  the  by-products  gained  in  the  purification  of  crude  pe- 
troleum. 

Hence  there  is  nothing  left  in  the  destructive  distillation  but 
to  work  wood  free  from  rosin  into  charcoal,  acetic  acid  and 
methyl  alcohol  as  chief  products,  and  to  consider  all  other 
products  as  by-products,  to  be  utilized  as  opportunity  offers  and 
eventually  to  be  used  as  fuel  in  the  factory.  When  working 
with  wood  rich  in  rosin,  it  is  best  first  to  obtain  acetic  acid  and 
wood  spirit  at  a  low  temperature,  and  then  to  raise  the  heat  to 
such  a  degree  as  is  required  to  gain  the  total  quantity  of  tar, 
since  from  this  tar,  by  subjecting  it  to  further  treatment,  tar 
oil  can  advantageously  be  prepared.  * 

Wood-tar  varies  in  character  with  the  kind  of  wood  from 
which  it  is  obtained,  that  derived  from  resinous  woods  being 
considered  the  more  valuable  on  account  of  its  content  of 
rosin.  When  wood  is  distilled  in  retorts,  the  portion  of  tar 
separated  from  the  crude  wood-vinegar  by  settling  and  that 
skimmed  off  of  the  top  of  the  neutralized  wood-vinegar  are 
united,  and,  after  washing  with  water,  may  be  sold  in  the 
crude  state  as  u  raw  tar"  or  as  "  retort  tar."  It  is  used  for 
preserving  wood,  for  making  roofing  felts,  as  an  antiseptic,  and 
for  the  preparation  of  wagon  grease  and  other  low-grade  lubri- 
cants. In  addition  to  the  tar  separated  by  settling,  the  crude 
wood-vinegar  contains  considerable  tar  held  in  solution  by  the 
acids  and  alcohol  present,  which  is  recovered  when  the  wood- 
vinegar  is  distilled,  and  constitutes  what  is  known  as  "  boiled 
tar."  It  may  be  sold  as  such  or  burned  under  the  retort,  or 
it  may  be  mixed  up  with  the  raw  tar  and  subjected  to  any 
desired  treatment. 

By  the  destructive  distillation  of  resinous  woods  tar  oil  con- 
taining turpentine  is  also  obtained,  but  less  wood  vinegar, 
eventually  calcium  acetate.  From  50  cubic  meters  of  air-dry 


248  MANUFACTURE    OF    VINEGAR. 

resinous  wood  are  obtained  about  4600  to  4750  kilogrammes 
charcoal,  1500  kilogrammes  tar,  400  kilogrammes  tar  oil,  450 
kilogrammes  calcium  acetate,  75  to  100  kilogrammes  wood- 
alcohol. 

Properties  of  the  Combinations  formed  in  the  Destructive  Distil" 
lation  of  Wood. — Of  the  many  bodies  formed  in  the  destructive 
distillation  of  wood,  only  a  few  are  of  importance,  these  being 
especially  acetic  acid,  wood  spirit  and  the  combinations  and 
products  of  decomposition  originating  from  these  two  bodies ; 
further  the  combinations  which  can  be  obtained  from  the  tar, 
namely  :  Creosote  and  tar  oils. 

Acetic  acid. — The  physical  and  chemical  properties  of  acetic 
acid  have  already  been  described  on  p.  27.  Of  the  products  of 
decomposition  which  acetic  acid  may  yield,  those  formed  by  the 
action  of  heat  are  here  of  special  interest.  Heated  by  itself, 
acetic  acid  can  stand  comparatively  very  high  temperatures 
without  suffering  decomposition,  and  acetic  acid  vapor  can,  for 
instance,  be  conducted  through  a  red-hot  porcelain  tube  without 
being  decomposed.  However,  decomposition  takes  place  al- 
ready at  a  slight  red  heat  when  the  vapor  comes  in  contact  with 
glowing  coal,  as  is  the  case  in  the  destructive  distillation  of  wood. 
If  acetic  acid  vapor  remains  for  some  time  in  contact  with  such 
coal,  a  gas  mixture,  consisting  of  methane,  carbonic  acid' and 
carbonic  oxide  is  formed,  the  latter  originating  from  the  action 
of  the  coal  upon  the  carbonic  acid  : 

C2H4O2  =  CH4  -f    CO2. 

acetic  acid,     methane,    carbonic  acid. 

Acetone.  At  a  less  high  temperature,  acetone,  CH3CO.CH3,  is 
formed  by  the  decomposition  of  acetic  acid  ;  its  formation  is 
illustrated  by  the  following  equation  : 

2(C2H402)  =  CaTT60  4-      C02        +H2O. 
acetic  acid  acetone      carbonic  acid       water. 

Acetone  is  always  found  in  wood  vinegar,  and  in  a  pure  state 
is  a  liquid  boiling  at  132.8°  F.,  of  specific  gravity  0.814,  of  a 


WOOD    VINEGAR    AND    OTHER    BY-PRODUCTS.  249 

pleasant  aromatic  odor  and  a  pungent  taste.  It  burns  with  a 
brilliant  flame  and  is  miscible  in  all  proportions  with  water, 
alcohol  and  ether.  It  is  an  excellent  solvent  for  fats,  resins, 
camphor,  volatile  oils,  gun  cotton,  etc.,  and  in  modern  times 
quite  large  quantities  of  it  are  employed  in  the  manufacture  of 
smokeless  gunpowder. 

Methyl  acetate  is  in  the  chemical  sense  an  acetic  methyl  ester. 
This  ester  is  formed  by  the  combination  of  acetic  acid  with 
methyl  alcohol,  water  being  withdrawn : 

CH,.CQQ£I  +  CH3OH  =  CH3.COO.CH3  -|-  H2O. 

By  treatment  with  alkalies  such  esters  are  saponified,  whereby 
the  alcohol  and  the  salt  of  the  acid  are  again  formed.  This  is 
also  the  case  with  the  methyl  acetate  contained  in  crude  wood- 
vinegar  when  it  is  distilled  with  the  addition  of  lime.  But, 
as  a  rule,  small  quantities  of  it  escape  saponification,  and  for 
this  reason  the  presence  of  acetic  methyl  ester  can  always  be 
established  in  crude  wood-vinegar. 

Aldehyde  or  acetaldehyde  has  already  been  described  on  page 
24.  It  is  a  constant  constituent  of  the  products  of  the 
destructive  distillation  of  wood. 

Methyl  alcohol  or  wood  spirit,  CH3OH,  in  a  pure  state,  is  a 
colorless,  mobile  liquid  having  a  peculiar  odor  and  burning 
taste.  When  ignited  it  burns  with  a  slightly  luminous  flame. 
It  boils  at  149°  F.  and  has  a  specific  gravity  of  0.798  at  32°  F. 
It  is  a  solvent  for  resins  and  essential  oils,  and  for  this  reason 
is  used  in  the  manufacture  of  lacquers  and  varnishes.  It  may 
also  be  employed  as  fuel  in  place  of  ordinary  alcohol.  In 
modern  times  it  has  become  an  important  article  of  commerce, 
it  being  largely  used  in  the  manufacture  of  aniline  colors  and 
for  many  other  purposes. 

Crude  wood  spirit  as  originally  obtained  from  wood-vinegar 
is  a  mixture  of  methyl  alcohol,  acetic  methyl  ester,  all  the 
readily  volatile  products  of  decomposition  of  acetic  acid  (ace- 
tone, aldehyde,  dimethyl  acetate)  and  the  readily  volatile 


250  MANUFACTURE    OF    VINEGAR. 

hydrocarbons.  The  preparation  of  pure  methyl  alcohol,  which 
will  be  referred  to  later  on,  is  therefore  connected  with  certain 
difficulties. 

Tar  Products — Hydrocarbons  of  the  series  CnH2n-6.  There 
is  considerable  variation  in  the  properties  of  the  products  oc- 
curring in  tar,  as  far  as  they  are  hydrocarbons.  Those  which 
are  liquid  at  the  ordinary  temperature  are  of  slight  specific 
gravity  but  have  different  boiling-points  and  belong  to  differ- 
ent series  composed  according  to  a  certain  type.  The  best 
known  are  those  of  the  series  CnH2n_6)  mentioned  below. 

Benzene  boils  at  .    .    -    .  179.6°  F,  Specific  gravity  .    .    .  .0.850 

Toluene         "      ....  231.8°  F.  "             "        .    .    .  .  0.870 

Xylene         "      ....  282.2°  F.  "            "        .    .    .  .  0.875 

Cumene        "      ....  330.8°  F.  "                      .    .    .  .  0.887 

Cymene        "      .   .    .    .  345.2°  F.  'k        ...  .0.850 

These  bodies  possess  the  property  of  yielding  by  substitu- 
tion bases  which  by  treatment  with  oxidizing  bodies  can  be 
converted  into  coloring  matters,  the  so-called  tar  or  aniline 
colors.  As  an  example  may  here  be  mentioned  the  conver- 
sion of  benzene.  Benzene  has  the  formula  C6H6.  By  con- 

r\    TT      "| 

version  of  benzene  into  nitro-benzene  =     6     5  >  and  treat- 

N02    J 

ment  of  the  latter  with  hydrogen  at  the  nascent  moment, 
aniline  is  formed  : 

°«E«  j+6H==C6N6.NHa 

Nitre-benzine.  Aniline. 

According  to  the  same  scheme,  nitro-combinations  and 
amines  can  be  prepared  from  toluene,  cumene,  and  from  all 
other  hydrocarbons  belonging  to  this  series  which  can  by  suit- 
able treatment  be  converted  into  coloring  matters. 

At  present  aniline  colors  are  exclusively  obtained  from  coal 
tar,  but  there  is  no  doubt  that  they  can  also  be  prepared  from 
wood  tar,  though  thus  far  only  experiments  have  been  made 


WOOD    VINEGAR    AND    OTHER    BY-PRODUCTS.  251 

in   this  direction,  which,  however,  have  proved  highly  suc- 
cessful. 

Besides  the  hydrocarbons,  benzene,  toluene,  etc.,  boiling  at  a 
higher  temperature,  the  presence  in  wood  tar  of  a  few  others, 
distinguished  by  very  low  boiling  points  and  slight  specific 
gravity,  has  been  established.  Such  are: 

Iridol  boils  at  ,    .    .  116.6°  F.     Specific  gravity 0.660 

Citriol     "  .    .    .  125.60  F.          tfc             " 0.700 

Kubidol"  .   .   .134. 60  F.          "•            "      0.750 

Coridol    "  ...  140°     F.          "             "      0.800 

Benzidol1'  -    .    .158°     F.          "             "      0.850 

By  treatment  with  nitric  acid,  these  hydrocarbons  can  also 
be  converted  into  nitro-combinations  from  which,  by  reduc- 
tion, amines  can  be  prepared,  which  may  be  converted  into 
colored  combinations.  However,  thus  far  these  bodies  have 
not  been  thoroughly  examined. 

Naphthalene  and  Paraffin. — These  two  hydrocarbons,  which 
also  occur  in  wood  tar,  are  solid  at  the  ordinary  temperature 
and  are  distinguished  by  high  boiling  points.  Naphthalene 
crystallizes  in  white  rhombic  leaflets  with  a  peculiar  odor  and 
burning  taste.  It  fuses  at  174.2°  F.  and  boils  at  424.4°  F. 
Its  composition  is  C10H8.  By  treating  with  nitric  acid, 
naphthalene  may  be  converted  into  nitronaphthalene, 
C10H7N02,  and  from  the  latter  naph thy lamine  is  prepared, 
which  serves  for  the  manufacture  of  yellow  and  red  coloring 
matters. 

The  hydrocarbons  with  boiling  points  of  680°  to  752°  F., 
which  occur  in  wood  tar,  are  designated  paraffins  and  belong 
very  likely  to  the  series  CnH2n.  According  to  the  material 
from  which  they  are  obtained,  the  melting  points  of  the  par- 
affins vary,  and  all  the  combinations  belonging  to  this  group 
are  distinguished  by  their  great  chemical  indifference. 

Many  varieties  of  wood  tar  are  of  a  viscous  and  gritty 
nature,  which  indicates  a  large  content  of  paraffin.  In  fact, 
paraffin  was  first  prepared  from  beech-wood  tar  by  Reichen- 


252  MANUFACTURE    OF    VINEGAR. 

bach.  However,  as  previously  mentioned,  there  is  at  present 
little  prospect  of  the  preparation  of  paraffin  from  wood-tar 
proving  remunerative,  on  account  of  the  competition  with  the 
article  obtained  from  crude  petroleum. 

Besides  the  hydrocarbons  mentioned,  there  occur  in  wood- 
tar  small  quantities  of  the  following  :  Chrysene,  C12H8,  retene, 
C18H18,  and  pyrine,  C15H15. 

Tar  Products  Containing  Oxygen  (Creosote).  —  The  combina- 
tions containing  oxygen  which  occur  in  wood-tar  are  either 
members  of  the  phenol  series  or  belong  to  the  guaiacol  series. 
The  liquid  known  as  wood-tar  creosote  consists  of  a  mixture 
of  combinations  belonging  to  both  series,  the  compounds  be- 
longing to  the  phenol  series  being  : 

Phenic  acid  or  carbolic  acid  °6]^5  |  O     C6H7O. 

Creosote  C6H4<°^      C7H8O. 

/OH 
Ethyl  phenate  or  phenetol  C6H3—  CH3     C8H10O. 


Among  these  acids,  carbolic  acid  occurs  in  smallest  quan- 
tity. The  combinations  belonging  -to  the  guaiacol  series, 
which  are  found  in  wood  tar  are  : 

OTT 
Pyrocatechin  or  oxyphenic  acid  C6H4<^  C6H6O2. 

OP  FT 
M  ethyl-pyrocatechin  or  guaiacol  C6H4<^rT  8    C7H8O2. 

/CHS 

Creosol  06H3—  OOH2  C8H10O2. 


Creosote  may  also  be  prepared  from  coal-tar  ;  chemically, 
however,  this  creosote  consists  almost  exclusively  of  carbolic 
acid,  and  cannot  be  used  for  medicinal  purposes. 

Wood-tar  creosote  is  a  fluid  of  a  peculiar  penetrating  smoky 
odor.  Applied  to  a  mucous  membrane  or  to  the  raw  cuticle, 
it  excites  severe  burning  pain,  coagulates  the  albumen  of  the 


WOOD    VINEGAR    AND    OTHER    BY-PRODUCTS.  253 

secretion,  and  may  even  produce  ulceration.  It  preserves 
meat  probably  in  consequence  of  its  behavior  with  albumen, 
and  the  preserving  action  of  smoking  meat  is  due  to  a  content 
of  this  body  in  wood-smoke. 

Since  the  introduction  of  the  manufacture  of  illuminating 
gas  from  wood,  wood-tar  creosotes  very  rich  in  carbolic  acid 
are  found  in  commerce,  and  this  may  be  explained  by  the 
conditions  under  which  the  tar  from  which  the  creosote  has 
been  obtained  has  been  formed. 

When  illuminating  gases  are  to  be  obtained  from  wood,  the 
latter  must  as  quickly  as  possible  be  heated  to  a  high  temper- 
ature, and  under  these  conditions  an  abundance  of  carbolic 
acid  is  formed  which  passes  into  the  creosote.  If,  on  the  other 
hand,  destructive  distillation  is  carried  on  at  a  slowly  increasing 
temperature,  tar  is  obtained  which  chiefly  contains  creosol  and 
guaiacol.  Since  carbolic  acid  is  comparatively  quite  a  poison- 
ous body,  creosote  intended  for  medicinal  use  should  only  be 
prepared  at  factories  which  carry  on  the  destructive  distillation 
of  wood  chiefly  for  the  purpose  of  obtaining  acetic  acid. 

Besides  the  above-described  constituents,  various  chemists 
have  mentioned  a  complete  series  of  compounds  as  occurring 
in  wood-tar.  It  can  scarcely  be  doubted  that  several,  but  lit- 
tle known,  bodies  which  have  not  yet  been  prepared  in  a  pure 
state  occur  in  wood-tar,  but  those  which  have  been  called 
eupione,  picamar,  kapnomar,  pittacal,  cedriret,  pyroxantho- 
gene,  mesite,  xylite,  etc.,  consist  very  likely  of  mixtures  of 
various  bodies.  As  far  as  these  compounds  are  known  they 
must  be  considered  as  hydrocarbons  belonging  to  various  series 
of  combinations.  A  few  of  them,  like  cedriret  and  chrysene, 
give  with  acids  characteristic  color  reactions,  and  pittacal  is 
itself  of  a  beautiful  dark  blue  color.  On  heating  it  evolves 
ammonia,  and  hence  it  contains  nitrogen  very  likely  in  the 
form  of  combinations  known  as  substituted  ammonias. 

None  of  these  combinations  have  thus  far  become  of  any 
technical  importance,  but  they  are  occasionally  observed  in 
the  purification  of  sodium  acetate.  The  melt  of  the  crude  salt 


254  MANUFACTURE    OF    VINEGAR. 

when  not  yet  sufficiently  roasted  yields,  when  treated  with 
water,  solutions  of  a  beautiful  blue,  violet,  red  to  orange  color, 
these  colorations  being  produced  by  the  products  of  decompo- 
sition of  the  tar  substances. 


CHAPTER  XXII. 

PREPARATION    OF    CHARCOAL,    WOOD    VINEGAR    AND    TAR 
IN    CLOSED    VESSELS. 

IN  installing  a  plant  for  the  purpose  of  utilizing  wood  in  a 
thermo-chemical  way,  i.  e.}  a  factory  in  which  chiefly  pure  acetic 
acid  and  wood  spirit,  and  eventually  the  tar-products — tar  oils 
and  creosote — are  to  be  produced,  apparatus  will  evidently 
have  to  be  selected,  the  arrangement  of  which  is  as  complete  as 
possible,  and  which,  besides  the  gaining  of  all  products  liquid 
at  the  ordinary  temperature,  allows  also  of  the  utilization  of  the 
large  quantities  of  gas  evolved  in  the  destructive  distillation  of 
wood.  Hence,  according  to  the  object  in  view  in  distilling 
wood,  the  arrangements  for  obtaining  the  products  of  distilla- 
tion may  be  of  very  varying  nature,  the  most  simple  being  a 
few  suitably-fitted  pipes  and  barrels.  Retorts  in  which  the 
temperature  can  be  accurately  regulated  are  the  most  compli- 
cated and  complete,  but  also  the  most  expensive,  apparatus. 

What  kind  of  apparatus  has  to  be  used  and  what  kind  of 
products  are  to  be  prepared,  depends  entirely  upon  local  condi- 
tions. Since  the  value  of  a  product  increases  in  proportion  to 
the  labor  expended  in  the  production  of  it,  a  manufacturer  who 
prepares,  besides  pure  acetic  acid  and  wood  spirit,  also  tar  oils 
and  creosote,  will  thus  realize  the  greatest  profit  from  the 
wood,  but  to  attain  this  object  the  establishment  of  a  plant 
with  all  the  apparatus  required  for  this  purpose  is  necessary. 

However,  many  a  proprietor  of  woodland  does  not  care  to 
manufacture  pure  products  in  a  special  factory,  but  desires, 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS.  255 

by  the  expenditure  of  a  small  sum,  to  obtain  from  his  wood, 
besides  charcoal,  also  wood-vinegar  and  eventually  tar,  in  order 
to  realize,  by  the  sale  of  these  raw  products,  a  larger  profit 
from  his  wood  than  is  attainable  by  charring  alone.  In  such 
a  case  the  principle  of  division  of  labor,  and  eventually  associ- 
ation deserves  recommendation,  so  that  the  proprietors  of  the 
woodland  would  prepare  charcoal  besides  wood-vinegar  and 
tar  and  sell  these  products,  or  what  is  still  better,  work  them 
further  in  a  factory  erected  at  joint  expense. 

Some  readers  may  ask  the  question  whether  it  is  possible  to 
utilize  large  quantities  of  wood  by  employing  them  for  the 
manufacture  of  products  of  destructive  distillation.  This  ques- 
tion may  be  unconditionally  answered  in  the  affirmative,  since 
in  consequence  of  the  high  and  steadily  increasing  tax  on  alco- 
hol levied  in  most  countries,  the  price  of  table  vinegar  must 
constantly  rise. 

There  are  but  two  processes  by  which  acetic  acid  on  a  large 
scale  can  be  prepared,  namely,  from  alcohol  and  from  wood. 
Up  to  the  present  time  alcohol  can  only  be  obtained  from  the 
products  of  agriculture,  the  chief  raw  materials  being  grain 
and  potatoes,  and  eventually  grapes  and  certain  varieties  of 
fruit,  especially  apples. 

By  taking  into  consideration  the  great  expense  of  labor  re- 
quired to  obtain  these  products  of  the  soil  and  to  manufacture 
alcohol  and  acetic  acid  from  them,  it  will  be  evident  that  the 
price  of  this  acetic  acid  must  be  greater  than  of  that  which  can 
in  a  short  time  be  prepared  from  wood.  Furthermore,  vinegar 
prepared  from  alcohol  is  never  pure,  i.  e.,  it  does  not  consist 
only  of  acetic  anhydride  and  water,  but  always  contains  quite 
a  quantity  of  foreign  substances  in  solution,  and  besides  is  very 
poor  in  acetic  acid.  To  obtain  the  latter  pure  and  in  a  highly 
concentrated  state,  vinegar  has  to  undergo  almost  exactly  the 
same  chemical  manipulations  to  which  wood  vinegar  has  to  be 
subjected  in  order  to  prepare  from  it  pure  concentrated  acetic 
acid,  but  the  expense  of  preparing  such  acetic  acid  would  be 
very  great. 


256  MANUFACTURE    OF    VINEGAR. 

Pure  concentrated  acetic  acid  is  at  present  used  on  an  ex- 
tensive scale  in  the  chemical  industries,  and  is  also  more  and 
more  employed  in  the  preparation  of  table  vinegar,  since  there 
is  no  difference  between  pure  acetic  acid  prepared  from  wood 
and  that  prepared  from  alcohol.  Wood  vinegar,  however,  can 
be  utilized  for  other  purposes  besides  the  preparation  of  pure 
acetic  acid,  it  being  in  consequence  of  its  content  of  tar  pro- 
ducts, which  have  an  antiseptic  effect,  an  excellent  preserva- 
tive of  wood,  and  the  process  of  impregnating  the  latter  with 
it  is  decidedly  cheaper  than  most  methods  in  which  other 
bodies  are  employed  for  the  purpose.  • 

When  only  acetic  acid,  wood  spirit  and  tar  are  to  be  pro- 
duced, wood  waste  of  all  kinds,  for  instance,  saw-dust,  ex- 
hausted shavings  of  dye-woods,  spent  tan,  can  be  advanta- 
geously worked.  If  the  charcoal  obtained  from  such  material 
is  to  be  used  as  fuel,  it  must,  on  account  of  the  smallness  of 
the  pieces,  be  moulded  to  briquettes  by  a  machine  constructed 
for  the  purpose. 

Kilns  or  Ovens  and  Retorts. — The  chief  object  of  the  oldest 
method  of  charring  wood,  as  still  carried  on  in  some  localities, 
is  the  production  of  charcoal  without  regard  to  the  recovery  of 
the  available  by-products.  For  this  purpose  the  wood  under 
a  moveable  covering  is  burnt  with  the  access  of  air  in  heaps 
or  pits  in  the  immediate  neighborhood  of  where  it  is  cut.  The 
attempt  to  obtain  all  the  products  simultaneously,  with  a 
greater  amount  of  charcoal,  probably  first  led  to  the  substitu- 
tion of  stationary  apparatus,  either  of  brick-work  or  iron,  in 
place  of  the  covered  heaps.  Some  of  these  arrangements  are 
calculated,  like  the  heaps,  to  produce  the  necessary  tempera- 
ture for  charring,  by  the  combustion  of  a  portion  of  the  wood, 
and  the  admission  of  a  little  air,  such  as  kilns,  the  sides  of 
which  form  a  fixed  covering  for  the  substances  to  be  charred. 
In  others  the  portion  of  the  wood  destined  to  produce  the  heat 
is  entirely  separated  from  that  to  be  charred,  the  latter  being 
placed  inside,  the  former  outside,  the  kiln.  The  yield  of  ace- 
tate and  alcohol  is  very  low  even  in  the  best  of  kilns,  and  the 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS.  257 

use  of  the  latter  has  been  almost  entirely  abandoned,  they  be- 
ing now  only  employed  in  localities  where  charcoal  is  prac- 
tically the  only  product  recovered.  For  the  sake  of  complete- 
ness a  few  of  the  older  constructions  will  be  described. 

Schwartz's  Oven. — The  oven  introduced  by  Schwartz  into 
Sweden  is  based  upon  the  principle  that  the  hot  gases  furnished 
by  a  special  furnace  must  pass  through  the  wood  piled  in  a 
closed  space  and  heat  it  sufficiently  for  destructive  distillation. 
The  construction  is  shown  in  Figs.  54,  55  and  56.  Fig.  54  is 
a  ground  plan,  Fig.  55,  a  section  of  the  elevation  following  the 
lines  dd,  and  Fig.  56,  another  section  following  the  lines  cc. 
In  the  illustrations  A  A  is  the  space  where  the  wood  is  carbon- 
ized, b,  apertures  through  which  the  wood  is  brought  into  the 
oven,  and  the  charcoal  withdrawn  ;  c  c,  the  fire-places  for  heat- 
ing the  oven  ;  d  d,  openings  through  which  the  smoke,  car- 
bonic acid,  acetic  acid,  oleaginous  and  tarry  substances  pass  off 
through  the  pipes  g  g,  and  thence  through  the  condensers  into 
the  chimney  ;  e  e  are  knee-pipes  which  convey  the  tar  condensed 
into  the  vessels// — Fig.  55.  The  bend  in  the  pipes  prevents 
the  access  of  air  into  the  apparatus.  H  H  H  H  are  wooden 
channels  wherein  the  acid  and  oleaginous  matters  condense  ;  i 
is  the  chimney  and  k  a  small  opening  in  the  chimney,  where  a 
fire  is  lighted  to  establish  a  powerful  draught.  The  oven  walls 
are  of  fire-brick  or  may  be  of  two  rows  of  ordinary  brick,  the 
interspace  being  filled  with  clay  and  sand.  The  oven  is  first 
charged  with  the  heaviest  blocks  of  wood,  and  between  these 
smaller  wood  is  introduced,  for  the  purpose  of  making  the  in- 
terior more  permeable  to  the  action  of  the  fire.  All  the  orifices 
of  the  oven  are  then  closed,  and  the  fires  at  c  c  lighted,  the 
current  of  air  being  instituted  in  i  by  lighting  a  fire  at  k  as 
above  mentioned.  The  blaze  of  the  fire  traverses  the  oven 
and  carbonizes  the  charge  of  wood,  and  the  smoke  and  other 
vapors  from  the  oven  pass  by  the  exit  pipes  d  d  into  g  g, 
whence  they  escape  to  the  condensers  H  H,  and  thence  to  the 
chimney  i.  The  charge  is  known  to  be  completely  carbonized 
when  the  smoke  issuing  at  i,  which  is  at  first  black  and  heavy, 
17 


258 


MANUFACTURE    OF    VINEGAR. 


becomes   bluish  and   light.      The   chimney    passage  is   then 
closed,   and  the  opening  of  the  pipes  d  d  stopped  up  with 


FIG.  54. 


FIG.  55. 


FIG  56. 


wooden  plugs  and  then  well  luted  with  plastic  clay  ;  the  fire- 
doors  are  closed  and  the  oven  left  to  cool.  At  the  end  of  the 
second  day,  two  holes  in  the  top  of  the  oven  which  hitherto 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS. 


259 


had  been  closed  air-tight,  are  opened,  and  water  is  introduced 
to  extinguish  the  red-hot  charcoal.  The  openings  are  again 
closed  for  a  longer  period,  and  when  the  oven  gets  a  little 
cooler,  more  water  is  added.  If  any  red  sparks  are  observed r 
the  openings  and  pipes  must  be  carefully  stopped  up,  so  as  to- 
prevent  the  formation  of  a  current  of  air,  as  this  would  occa- 
sion the  combustion  of  the  charcoal  and  consequently  lessen 
the  product. 

Great  care  has  to  be  exercised  in  accurately  regulating  the 
access  of  air,  since  the  smallest  quantity  of  atmospheric  oxygen 
which  passes  through  the  fire-room  without  being  consumed 
causes  a  corresponding  loss  of  material  in  the  space  where  the 

FIG.  57. 


wood  is  carbonized.  Since  notwithstanding  the  utmost  care 
and  attention,  the  access  of  oxygen  can  never  be  entirely 
avoided,  this  oven  will  seldom  be  used  where  the  chief  object 
is  to  obtain  as  large  a  quantity  of  acetic  acid  as  possible.  An 
essential  improvement  in  the  oven  might  be  made  by  intro- 
ducing generator  gases  in  the  heating  places  and  burning 
them  by  the  admission  of  just  a  sufficient  quantity  of  air,  which 
could  readily  be  accurately  regulated,  so  that  a  slight  reduc- 
ing atmosphere  would  always  prevail  in  the  oven. 

Reichenbach' s  oven,  Fig.  57,  is  a  square  construction  with 
double  walls,  the  inner  wall  of  fire-brick  and  the  outer  of 
ordinary  brick.  The  space  between  the  two  walls  is  filled 


260 


MANUFACTURE    OF    VINEGAR. 


with  sand.  The  oven  is  heated  by  pipes  about  2  feet  in  diam- 
eter which  run  from  one  end  of  the  wall  to  the  other,  and  are 
seen  in  the  illustration  at  a,  6,  c,  d  and  m,  n.  o,  p.  The  appa- 
ratus having  been  filled  with  wood,  the  upper  portion  is  cov- 
ered with  a  layer  of  sods  and  earth,  or  with  iron  plates,  the 
joints  of  the  latter  being  carefully  luted  with  clay.  A  fire  is 
then  lighted  in  the  fire-places  in  front  of  p  and  d,  which  raises 
the  temperature  of  the  pipes  so  high  as  to  cause  them  to  glow. 
The  wood  in  the  surrounding  spaces  of  the  oven  abstracts  the 
heat  and  is  thereby  carbonized,  the  volatile  products  of  which 
pass  off  at  the  bottom  of  the  oven  through  the  openings  at  x, 


into  the  conduit/,  #,  h,  and  through  y  at  the  opposite  side  into 
a  similar  conduit.  Both  products  intermix  in  the  pipe  ki, 
where  the  tar  is  partly  deposited.  From  the  pipe  ki,  the 
acetic  acid  vapors  are  carried  off  to  the  condenser. 

Swedish  oven.  This  oven  is  shown  in  Fig.  58.  The  space 
G  where  the  wood  is  carbonized  is  vaulted  and  is  provided  on 
top  with  an  aperture  for  charging  the  wood,  which  after  the 
vault  is  filled,  is  closed  by  a  heavy  lid  luted  with  clay.  The 
pipe  A  serves  for  carrying  off  the  products  of  distillation.  The 
bottom  of  the  vault  is  conical,  and  in  the  center  is  provided  with 
thetgrate  R,  below  which  is  the  ash-pit  C,  which  can  be  closed 
by  an  accurately-fitting  slide  S.  The  door  Tt  which  is  bricked 


WOOD    VINEGAR    AND    TAK    IN    CLOSED    VESSELS.  261 

up  during  the  process  of  carbonization,  serves  for  withdrawing 
the  finished  charcoal,  and  also  for  the  introduction  of  a  portion 
of  the  wood.  It  is  immediately  closed  after  the  introduction 
through  it  of  some  glowing  coals.  The  effect  of  the  latter  is  to 
ignite  a  portion  of  the  wood,  and  combustion  is  conducted  by 
setting  the  slide  8  so  that  the  vapors  are  cooled  with  a  certain 
uniformity.  In  a  short  time  the  wood  and  the  walls  of  the 
oven  become  so  thoroughly  heated  that  combustion  can  be 
entirely  interrupted  by  closing  the  slide  S,  distillation  being 
completed  by  the  heat  accumulated  in  the  oven. 

An  oven  of  a  somewhat  different  construction  is  shown  in 
cross-section  in  Fig.  59,  and  in  ground  plan  in  Fig,  60.     The 


FIG.  o9. 


FIG.  60. 


space  in  which  the  wood  is  carbonized  is  in  the  form  of  a  cyl- 
inder and  passes  above  into  a  vault  closed  by  a  heavy  iron  lid 
a.  The  brick  work  of  this  space  is  surrounded  by  another 
brick  work  6,  and  the  fire  which  is  ignited  at  the  opposite  side 
d  circulates  between  the  two  walls  in  the  space  c  c.  On  the 
upper  portion  of  the  oven,  at  d,  are  apertures  provided  with 
slides,  which  serve  for  regulating  the  fire.  The  products  of 
distillation  escape  through  the  pipe  e  on  the  bottom  of  the 
carbonizing  space. 

The  oven  is  heated  so  that  the  interior  wall  becomes  red-hot. 
Firing  is  interrupted  when  no  more  vapors  escape  from* the 
pipe  e.  The  slide  at  d  is  then  closed  and  the  oven  left  to  cool 


:262  MANUFACTURE    OF    VINEGAR. 

'until  the  charcoal  is  sufficiently  cooled  off  to  allow  of  it  being 
withdrawn  without  fear  of  ignition. 

*Carbo-oven. — In  this  oven  carbonization  is  effected  in  a 
WTo-ught-iron  vertical  cylinder  with  a  capacity  of  300  to  400 
cubic  meters  of  wood.  The  wood  is  introduced  through  open- 
ings in  the  wrought-iron  cover  of  the  cylinder.  The  products 
of  distillation  pass  out  through  a  pipe  branching  off  from  the 
lowest  part  of  the  bottom.  An  outlet  on  the  side  of  the  cyl- 
inder serves  for  emptying  the  latter. 

Heating  is  effected  by  tire-gases  produced  in  a  separate 
furnace,  which  pass  through  spiral  flues  surrounding  the 
wrought-iron  cylinder.  The  lower  portion  of  the  cylinder  is 
protected  by  brickwork  from  the  direct  action  of  the  fire-gases. 

In  the  center  of  the  cylinder  stands  a  large  vertical  heating- 
pipe  divided  into  halves  by  a  partition.  The  non-condensable 
gases,  as  well  as  the  air  required  for  their  combustion,  can 
pass  in  through  two  pipes  entering  the  lower  part.  The 
smoke-gases  coming  from  the  last  flue  may  also  be  conducted 
through  this  heating  pipe  and,  mixed  with  the  combustion 
products  of  the  wood-gases,  escape  to  the  chimney. 

Retorts. — The  various  forms  of  apparatus  for  the  destructive 
distillation  of  wood  previously  described  are  of  such  a  con- 
struction as  to  exclude  uninterrupted  operation.  When  a 
charge  has  been  distilled  off,  the  kiln  or  oven  has  to  stand  till 
the  charcoal  is  sufficiently  cooled  off  to  allow  of  its  being  with- 
drawn. When  this  has  been  done  the  oven  must  be  again 
charged,  heated  and  so  on.  This  is  evidently  connected  not 
only  with  considerable  loss  of  time,  but  also  of  heat,  and  it 
has  been  endeavored  to  overcome  this  drawback  by  the  use  of 
retort-ovens. 

By  heating  wood  in  a  retort  closed  air-tight  with  the  ex- 
ception of  an  opening  for  the  escape  of  the  products  of  distil- 
lation, and  by  fitting  to  this  opening  a  condenser  of  suitable 
•construction,  an  apparatus  is  obtained  with  which  all  vapor- 
iform  products  escaping  from  the  wood  can  be  recovered. 
Such  an  apparatus,  though  the  most  expensive,  is  the  best  for 
the  production  of  wood  vinegar. 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS. 


263 


'a.  Horizontal  retorts. — The  arrangement  of  an  apparatus  for 
the  distillation  of  wood  is  very  similar  to  that  used  for  the 
production  of  illuminating  gas  from  coal,  the  essential  differ- 
ence being  that  the  retorts  for  the  distillation  of  wood  must 
lie  in  fire-places  which  allow  of  the  heat  being  slowly  and 
uniformly  raised,  while  in  making  illuminating  gas  rapid 
raising  of  the  heat  is  required.  Clay  being  a  worse  conductor 
of  heat  than  iron,  the  use  of  retorts  of  this  material  would 
apparently  seem  advisable  for  the  destructive  distillation  of 
wood.  However,  clay  retorts  have  the  drawback  of  being 
fragile  and  besides  cracks  are  readily  formed  through  which  a 


FIG.  61. 


FIG.  62. 


portion  of  the  vapors  would  escape.  For  this  reason  iron  retorts 
are  as  a  rule  used.  Cast  iron  retorts  do  not  readily  burn 
through  and  are  but  little  affected  by  the  vapors  of  the  acid, 
but  they  have  the  drawback  of  great  weight,  and  defective 
places  are  difficult  to  repair.  The  best  material  for  horizontal 
as  well  as  vertical  retorts  is  hot-riveted  boiler  plate  about  8 
millimeters  thick.  Defects  in  such  a  retort  can  be  readily 
repaired  by  riveting  a  piece  of  boiler  plate  upon  the  defective 
place. 

A  wrought-iron  retort  of  very  suitable  construction  is  shown 
in  Figs.  61  and  62.  It  consists  of  a  cylinder  2.2  meters  long 
and  1  meter  in  diameter.  On  the  back  end  the  retort  passes, 


264 


MANUFACTURE    OF    VINEGAR. 


as  seen  in  the  illustration,  into  a  pipe  of  such  a  length  that 
about  30  centimeters  of  it  project  from  the  brick  work  of  the 
oven.  In  front  the  retort  is  secured  to  a  cast-iron  ring,  in  the 
groove  of  which  fits  a  sheet-iron  door.  This  door  is  pressed 
against  the  ring  by  a  screw  and  the  joint  is  made  air-tight  by 
luting  with  clay.  For  the  rapid  withdrawal  of  the  charcoal, 
the  interior  of  the  retort  is  furnished  with  a  sheet-iron  disk 
supported  by  two  rods  riveted  to  it.  To  the  center  of  this  disk 
a  chain  is  fastened  which  lies  upon  the  bottom  of  the  retort. 
When  the  door  of  the  retort  is  opened  the  chain  is  seized  with 
a  hook  and  on  being  drawn  forward  the  sheet-iron  disk  pushes 
the  charcoal  out. 

To  protect  the  portion  of  the  retort  which  comes  in  direct 
contact  with  the  flame  it  is  advisable  to  apply  to  it  repeatedly 

FIG.  63. 


a  mixture  of  clay  and  cow  hair.  This  prevents  quite  well  the 
formation  of  burnt  iron  which  scales  off  from  the  portions 
directly  heated. 

Fig.  63  shows  the  manner  of  bricking  in  six  retorts,  two 
being  placed  in  one  fire  place.  In  this  construction,  as  will 
be  seen  from  the  illustration,  the  fire-gases  pass  directly  into 
the  chimney  which  is  equivalent  to  a  waste  of  heat.  How- 
ever, this  heat  can  be  completely  utilized  either  by  placing 
upon  the  retort-oven  a  pan  in  which  the  solution  of  crude 
sodium  acetate  may  be  evaporated,  or  the  fire-gases  may  be 
used  for  heating  a  room  in  which  the  wood  for  the  next  oper- 
ation is  dried.  In  working  wood  very  poor  in  water,  a  smaller 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS. 


265 


quantity  of  wood  vinegar  is  to  be  sure  obtained  than  with  the 
use  of  ordinary  air-dry  wood,  but  it  is  correspondingly  richer 
in  acetic  acid. 


FIG.  64. 


In  Figs.  64  and  65,  a  a  a  are  the  wrought-iron  retorts,  b  the 
hearth,  c  c  the  flues,  d  the  chimney.  Over  the  somewhat 
conical  neck  of  the  retort  is  pushed  an  elbow  pipe  e  which 


FIG.  65. 


dips  into  the  receiver  F.  The  latter  is  a  cast-iron  pipe  1  to  2 
feet  in  diameter  according  to  the  number  of  retorts,  and  ex- 
tends the  entire  length  of  the  oven.  For  the  neck  of  each  re- 
tort it  carries  a  tubulure  5}  to  7}  inches  long.  The  object 


•266 


MANUFACTURE    OF    VINEGAR. 


of  the  receiver  is  to  receive  the  products  of  distillation  from  all 
the  retorts  and  at  the  same  time  to  hydraulically  close  the 
-elbow-pipe  of  each  receiver.  Hence  the  vapors  not  precipi- 
tated in  the  receiver  can  continue  their  way  through  g  to  the 
other  condensing  apparatus  h,  but  cannot  re-enter  the  retorts. 
This  is  of  no  slight  importance,  for  if  there  were  no  water- 
joint  and  the  vapors  should  from  any  cause  suddenly  cool  off, 
the  external  air  might  penetrate  into  the  retort,  and  the  latter 
being  filled  with  inflammable  gases  and  vapors  of  a  high  tem- 
perature, an  explosion  would  necessarily  follow.  For  making 
the  water-joint  it  suffices  for  the  elbow-pipes  to  dip  f  to  1  inch 

FIG.  66. 


into  the  fluid  into  the  receiver.  But  as  the  fluid  constantly 
increases,  provision  must  be  made  for  its  discharge  through  a 
pipe,  placed  below  or  on  the  side,  into  a  collecting  vessel 
located  in  another  apartment. 

In  many  plants  the  gases  escaping  from  the  condenser  are 
utilized  for  heating  by  conducting  them  under  the  retorts 
through  a  suitable  pipe  system.  However,  the  pipe-system 
should  be  so  arranged  as  to  allow  of  the  gas  being  conducted 
under  any  one  of  the  retorts  or  being  shut  off  from  it  in  case 
of  necessity,  because  if  distillation  progresses  too  rapidly,  the 
fire  under  a  retort  may  have  to  be  entirely  removed  in  order 
to  moderate  the  chemical  process  in  the  retort.  It  is  advisable 
to  arrange  the  gas  conduit  so  that  the  gas  can  also  be  used  for 
heating  other  apparatus,  for  instance,  evaporating  pans,  etc. 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS.  267 

In  this  country  what  is  known  as  the  oven-retort,  Fig.  66, 
is  largely  used  in  equipping  plants  for  hard-wood  distillation. 
This  retort  is  a  rectangular  wrought-iron  chamber,  a  common 
size  being  6  feet  wide,  7  feet  high  and  from  27  to  50  feet  long, 
according  as  it  is  intended  for  two  or  more  cars  loaded  with 
wood.  The  oven  is  set  in  brickwork  or  is  made  with  double 
iron  walls  with  an  air  space  between.  It  is  provided  with  a 
large  door  closing  air-tight,  and  is  heated  by  wood,  charcoal, 
coal  or  gas. 

When  distillation  is  finished  the  cover  of  the  retort  is  re- 
moved, and  the  glowing  charcoal  is  with  the  assistance  of  the 

FIG.  67. 


previously-described  contrivance  emptied  into  cans,  which  are 
immediately  closed  with  tightly-fitting  covers,  the  latter  being 
luted  with  clay  or  sand  to  prevent  ignition  of  the  glowing  coal 
by  the  entrance  of  air.  If  such  retorts  as  shown  in  Fig.  66 
are  used,  coolers,  Fig.  67,  similar  in  shape  are  employed,  in 
which  the  coal  is  allowed  to  remain  until  thoroughly  cool. 

b.  Vertical  Retorts. — The  principal  drawback  of  horizontal 
retorts  is  that,  on  the  one  hand,  charging  them  is  connected 
with  some  difficulty  in  case  they  are  longer  than  two  lengths 
of  the  wood,  and,  on  the  other,  that  defects  in  them  cannot 
as  a  rule  be  immediately  detected,  and  that  when  repairs  have 
to  be  made  they  have  to  be  taken  from  the  oven.  In  addi- 


268 


MANUFACTURE    OF    VINEGAR. 


tion  a  certain  number  of  sheet-iron  cans  have  to  be  provided' 
for  the  reception  of  the  charcoal  drawn  from  the  retorts. 

The  arrangement  of  the  retorts  so  that  they  can  be  lifted 
from  the  oven  and  replaced  by  others  has  many  advantages. 
The  operation  can  be  carried  on  without  interruption  by  re- 
moving a  retort  in  which  distillation  is  finished  and  replacing 
it  by  another,  in  which  distillation  at  once  recommences,  be- 
cause the  hot  brickwork  throws  out  heat  continuous!}',  and 
heating  need  to  be  interrupted  only  during  the  time  required 
for  lifting  out  the  retort  and  replacing  it  by  another. 

The  accompanying  illustrations  show  the  arrangement  of  the- 

FIG.  68. 


retort-ovens  and  the  lifting  apparatus  as  devised  by  Dr.  Josef 
Bersch.  Fig.  68  shows  a  retort  12  feet  high  with  a  diameter  of 
3  feet  and  3  inches.  It  is  constructed  of  boiler-plate  0.315 
inch  thick,  the  bottom,  i.  e.,  the  portion  which  is  exposed 
directly  to  the  fire,  being  of  plate  0.394  inch  thick.  The 
upper  portion  of  the  retort  is  provided  with  a  cast-iron  ring 
K  which,  when  the  retort  is  lowered  into  the  oven,  rests  upon  a 
flat  cast-iron  ring  P  placed  upon  the  brickwork.  On  this 
ring  are  four  eyes  $  which  serve  for  fastening  the  lifting  tackle, 
and  the  lid  of  the  retort  is  secured  by  four  pins  pushed  through 
the  openings  in  the  ring.  The  lid  of  the  retort  consists  of  a 
sheet-iron  disk,  provided  in  the  center  with  a  conical  head- 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS.  269 

piece  D  which  terminates  in  the  pipe  H  leading  to  the  con- 
denser. 

Figs.  69  and  70  show  the  retorts  placed  in  the  oven  and  the 
mechanical  contrivance  for  raising  and  lowering  the  retort  R. 
On  top  of  the  ovens  is  a  track  (7,  upon  which  runs  a  crane  with 
a  head-piece  having  the  form  of  a  truncated  cone.  The  track  is 
continued  from  the  last  oven  to  a  brick  wall  upon  which  it  rests, 
and  beneath  this  track  is  another  one,  which  runs  to  the  place 
where  the  charcoal  is  to  be  emptied  and  the  retort  is  to  be  re- 
filled with  wood.  The  function  of  this  mechanical  contrivance 

Fig.  69. 


is  as  follows  :  The  retort,  after  the  contents  have  been  distilled, 
is,  while  hot,  lifted  from  the  oven  by  pushing  the  crane  over  it 
and  drawing  it  into  the  hollow  pyramid.  The  crane  is  then 
pushed  over  the  opening  0,  upon  which  stands  a  carriage  K 
upon  the  other  track  E.  The  carriage  is  provided  with  a 
basket-like  arrangement  for  the  reception  of  the  retort.  The 
retort  having  been  lowered  into  the  basket,  the  latter  is  brought 
into  a  horizontal  position  by  turning  a  screw  without  end.  The 
carriage,  which  is  actually  a  dumping-car,  is  pushed  over  the 
pit  for  the  reception  of  the  charcoal,  and  the  retort,  the  lid  of 
which  is  now  taken  off,  is  sufficiently  inclined  to  allow  the  char- 


270 


MANUFACTURE    OF    VINEGAR. 


coal  to  fall  into  the  pit.  The  charcoal  is  protected  from  igni- 
tion by  being  covered  with  wet  charcoal  dust.  The  empty 
retort  is  then  again  brought  into  a  horizontal  position  and 
refilled  with  wood. 

While  the  retort  just  coming  from  the  oven  is  thus  handled, 
and  the  first  dumping-car  has  been  pushed  away,  another 
dumping-car  is  immediately  brought  from  a  side  track  &' under 

Fig.  70. 


the  crane,  the  retort  lifted  in,  the  crane  pushed  over  the  empty 
oven,  and  the  retort  lowered. 

Since  towards  the  end  of  distillation  the  greatest  heat  must 
be  applied  in  order  to  obtain  the  last  remnants  of  acetic  acid 
and  tar,  the  sides  of  the  oven  are  hottest  at  this  period.  If 
now  immediately  after  a  retort  with  charcoal  has  been  taken 
out,  another  one  charged  with  wood  is  brought  into  the  oven, 
the  heat  radiating  from  the  sides  of  the  oven  suffices  to  induce 
distillation,  and  the  fire  need  only  be  slightly  stirred  to  unin- 
terruptedly carry  on  the  operation. 

One  crane  and  two  dumping-cars  are  sufficient  for  attend- 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS.  271 

ing  twelve  to  eighteen  ovens  arranged  one  alongside  the  other. 
For  a  larger  number  of  retorts  it  is  advisable  to  have  two- 
cranes,  and  to  arrange  the  coarse  of  the  operation  as  follows : 
One  crane,  in  the  pyramid  of  which  is  suspended  a  retort 
filled  with  wood,  which  has  been  lifted  from  a  dumping-car 
standing,  for  instance,  on  the  right-hand  end  of  the  series  of 
ovens,  is  immediately  pushed  over  the  oven  as  soon  as  the  re- 
tort filled  with  charcoal  has  been  lifted  out,  and  the  retort  is 
then  lowered.  The  other  crane  is  pushed  to  the  left-hand 
end  of  the  series  of  ovens,  where  the  retort  is  lowered,  and 
so  on. 

By  the  employment  of  these  contrivances  the  time  required 
for  distillation  is  reduced  to  a  minimum,  the  operation  can  be 
carried  on  without  interruption,  and  it  is  not  necessary  to  pro- 
vide sheet-iron  cylinders  for  cooling  the  charcoal,  since  the- 
latter  is  dumped  from  the  retorts  directly  into  pits  between  the 
rails  upon  which  the  dumping  cars  run,  where  it  is  cooled  by 
covering  with  wet  charcoal  dust. 

Distilling  apparatus  for  wood  waste. — In  working  wood  and 
bark  in  the  various  trades  a  large  quantity  of  waste  results 
which,  in  most  cases,  is  used  as  fuel.  Such  waste  can,  however, 
be  utilized  to  greater  advantage  by  subjecting  it  to  destructive 
distillation  for  the  purpose  of  obtaining  wood-vinegar,  tar  and 
charcoal. 

Halliday's  apparatus  for  the  production  of  acetic  acid,  etc., 
from  sawdust,  spent  bark  from  tan-yards  and  dye  woods  ex.. 
hausted  of  their  coloring  matter,  is  shown  in  Fig.  71.  The 
waste  to  be  treated  is  introduced  into  a  hopper  B  placed  above 
the  front  end  of  an  ordinary  cylinder  C,  in  which  a  vertical 
screw  or  worm  revolves,  conveying  the  material,  and  in  proper 
quantities,  to  the  cylinder,  placed  in  a  horizontal  position, 
and  heated  by  means  of  a  furnace  H.  Another  revolving 
screw  or  worm  D  keeps  the  material  introduced  into  the  retort 
by  C  in  constant  agitation,  and  at  the  same  time  moves  it 
forward  to  the  end.  During  its  progress  through  the  retort 
the  materials  are  completely  carbonized  and  all  the  volatile 


•272 


MANUFACTURE    OF    VINEGAR. 


products  disengaged.  Two  pipes  branch  off  from  the  ulterior 
part  of  the  retort,  one  .F  passing  downward  and  dipping  into 
-an  air-tight  vessel  of  cast-iron,  or  a  cistern  of  water  G,  into 
which  the  carbonized  substance  falls.  The  other  ascending 
pipe  E  carries  off  the  volatile  products  of  the  distillation  into 
the  condenser,  consisting  of  pipes  of  copper  or  iron  immersed 
in  or  surrounded  by  water. 

The  arrangement  of  the  cylinder  A  with  the  screw  is  sim- 
ilar to  the  worms  used  for  moving  grain,  malt,  etc.,  in  a 
-horizontal  direction.  According  as  the  screw  revolves  with 

Fig.  71 


greater  or  less  rapidity,  the  materials  can  for  a  shorter  or 
longer  time  be  exposed  to  the  action  of  the  heat,  and  accord- 
ing to  well  authenticated  statements,  the  quantity  of  acetic 
acid  obtained  from  the  wood  substance  distilled  in  this  appa- 
ratus is  larger  than  that  derived  from  blocks  of  wood  stacked 
in  other  retorts. 

This  fact,  however,  cannot  be  ascribed  to  the  construction  of 
the  apparatus,  which  is  not  particularly  favorable,  but  is  ex- 
clusively due  to  the  condition  of  the  wood.  From  the  small 
particles  of  wood  the  products  of  distillation  escape  with  far 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS.  273 

greater  rapidity  than  from  the  large  blocks,  which  must  be 
very  hot  on  the  surface  before  their  interior  is  sufficiently 
heated  for  distillation  to  commence.  Hence  the  products  of 


FIG.  72. 


distillation  must  pass  through  the  strongly-heated  carbonized 
parts,  whereby  a  considerable  portion  of  the  acetic  acid  is  de- 
composed. 

Another  apparatus  suitable  for  the  distillation  of  sawdust, 
18 


274  MANUFACTURE    OF    VINEGAR. 

spent  tan-bark,  exhausted  dye  woods  and  waste  of  wood  in 
general,  is  shown  in  Fig.  72.  It  consists  of  an  iron  cylinder, 
18  feet  high  and  5}  feet  in  diameter,  which  contains  a  number 
of  bell-shaped  rings  placed  one  above  the  other.  In  this  man- 
ner a  kind  of  annular  cylinder  is  formed  which  below  termin- 
ates in  a  conical  space. 

The  materials  thrown  in  at  the  top  are  heated  in  the  cylin- 
der, and  the  vapors  in  the  cavities  of  the  bell-shaped  rings  pass 
upwards,  while  the  charcoal  falls  down  and  is  from  time  to 
time  removed.  In  removing  the  charcoal,  the  lower  portion 
of  the  cylinder  is  closed  by  a  slide,  so  that  by  introducing 
material  on  top  of  the  cylinder,  distillation  can  be  carried  on 
without  interruption. 

The  small  charcoal  resulting  in  the  destructive  distillation 
of  wood  waste,  may  be  utilized  in  various  ways.  A  portion 
burned  upon  a  grate  of  suitable  construction,  for  instance, 
a  step-grate,  serves  as  fuel  in  the  factory  itself,  while  the  re- 
mainder, especially  that  from  sawdust,  forms  in  the  finely 
divided  state  in  which  it  is  turned  out,  an  excellent  disinfect- 
ing agent. 

The  various  apparatus  employed  in  the  destructive  distilla- 
tion of  wood  having  now  been  described,  it  may  be  stated  that 
it  is  impossible  to  say  which  is  to  be  preferred,  this  depending 
largely  on  local  conditions.  The  decision  must  particularly  be 
influenced  by  the  fact  whether  the  charcoal  is  of  value  or  not. 
In  the  first  case  it  will  evidently  be  of  advantage  to  employ 
smaller  apparatus,  so  arranged  that  besides  thoroughly  car- 
bonized charcoal,  all  the  wood-vinegar  and  tar  are  obtained, 
and  further,  that  the  resulting  gases  can  be  employed  for 
heating  the  retorts. 

But  where  the  conditions  are  such  as  to  make  it  difficult  to 
realize  on  the  charcoal,  the  principal  profit  of  the  plant  will  be 
in  the  yield  of  acetic  acid  and  wood  spirit,  and  for  this  reason 
it  is  best  to  carry  on  the  destructive  distillation  of  wood  in 
very  large  retorts,  since  with  their  use  the  temperature  can  be 
raised  very  slowly,  whereby  wood-vinegar  very  rich  in  acetic 
acid  is  obtained. 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS.  275 

Coolers. — The  products  which  escape  in  the  destructive  dis- 
tillation of  wood  consist,  in  addition  to  acetic  acid,  water  and 
other  very  volatile  products,  of  very  large  quantities  of  gas. 
Since  the  current  of  gas  is  the  carrier  of  vapors,  and  consider- 
able quantities  of  gas  are  evolved  at  certain  stages  of  the  pro- 
cess, provision  must  be  made  for  the  thorough  condensation  of 
the  vapors  to  prevent  the  escape  into  the  air  of  large  quanti- 
ties of  valuable  products  of  distillation,  or  their  being  burned 
with  the  gases. 

In  plants  working  with  a  number  of  retorts,  the  discharge 
pipes  of  the  latter  enter  into  a  common  pipe  of  large  diameter, 
and  in  this  condensing  pipe,  which  in  a  short  time  after  the 
commencement  of  the  operation  becomes  very  hot,  the  vapors 
and  gases  entering  it  are  cooled  off  to  a  considerable  extent, 
since  the  condenser  in  consequence  of  its  large  surface  yields 
considerable  heat  to  the  surrounding  air.  A  portion  of  the 
heavier  volatile  tar  products  is  already  condensed  in  the  con- 
denser, and  is  drawn  off  by  means  of  a  faucet  in  the  lowest 
portion  of  the  pipe.  It  might  be  suitable  to  place  over  the- 
condenser  a  pipe  with  numerous  small  perforations,  so  that  a 
spray  of  water  in  such  quantity  that  it  immediately  evapo- 
rates, falls  constantly  upon  the  condenser. 

By  the  use  of  this  contrivance  not  only  a  large  portion  of 
the  vapors  are  liquefied,  but  another  advantage  is  attained. 
Since  by  this  cooling  the  tension  of  the  vapors  and  gases  in 
the  condenser  is  diminished,  the  vapors  formed  in  the  retorts 
pass  out  with  great  rapidity.  This  is  of  great  advantage, 
since  by  the  vapors  remaining  for  a  long  time  in  the  retort  a 
considerable  quantity  of  acetic  acid  is  decomposed.  Further- 
more, the  volume  of  non-condensed  vapors  is  considerably  de- 
creased, so  that  a  cooler  of  smaller  dimensions  can  be  used, 
than  would  be  possible  if  all  cooling  had  to  be  done  in  it. 

Counter-current  Pipe  Cooler. — The  arrangement  of  such  a 
cooler  is  shown  in  Fig.  73.  The  pipe  J9,  containing  the  vapors 
to  be  cooled,  is  surrounded  by  another  pipe  W,  filled  with 
water.  From  the  reservoir  placed  at  a  higher  level,  cold  water 


276 


MANUFACTURE    OF    VINEGAR. 


is  conducted  through  the  pipe  Z  to  the  lowest  part  of  IF,  and 
passing  through  the  latter,  runs  off  at  A.  Since  the  vapors  in 
the  lowest  part  of  D  have  already  been  cooled  off  to  a  great 
•extent,  they  yield  but  little  heat  to  the  water.  As  the  water 
•reaches  the  higher  portions  of  W,-it  constantly  acquires  a 
higher  temperature  from  the  heat  withdrawn  from  the  vapors, 
.and  rinally  runs  off  at  A.  With  a  sufficient  length  of  the  cool- 
ing pipes  and  a  powerful  current  of  water,  the  vapors  are  so 
completely  condensed  that  but  very  small  quantities  of  acetic 
^icid  and  wood  spirit  are  carried  away  by  the  current  of  gas. 
To  obtain  this  acetic  acid,  the  gas  before  being  burned  is 

FIG.  73. 


allowed  to  pass  through  a  cylinder  d,  see  Fig.  76,  which  is  from 
3J  to  4  feet  high  and  filled  with  limestone.  The  acetic  acid 
contained  in  the  gas  is  fixed  by  the  limestone  and  the  calcium 
acetate  thus  formed  can  be  obtained  by  lixiviation. 

The  cooling  pipes  should  be  of  considerable  length.  With 
six  retorts  in  operation  at  the  same  time,  the  length  of  the 
pipes  should  be  about  130  feet  and  their  diameter  5}  inches, 
since  otherwise  great  pressure  is  caused  in  the  apparatus  by 
back  pressure  of  the  gases,  which  results  in  a  decrease  in 
'the  yield  of  acetic  acid.  Hence  it  is  advisable  to  arrange  the 
upper  portion  of  the  cooling  apparatus  so  that  the  pipe  TFhas 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS. 


27T 


an  elliptical  cross  section  and  contains  two  pipes  D,  one  along- 
side the  other,  which  in  passing  out  from  this  portion  combine 
to  one  pipe. 

To  prevent  obstruction  in  the  pipes  by  the  collection  of  vis- 
cous tarry  substances,  it  is  recommended  to  give  them  consid- 
erable inclination  and  to  connect  them  so  that,  in  case  of  neces- 
sity, the  interior  of  each  pipe  can  be  cleansed  with  a  brush. 
Fig.  74  shows  the  most  suitable  way  of  connecting  two  pipes. 
The  upper  pipe  is  connected  writh  the  lower  one  by  means  of 
a  curved  joint  secured  by  screws. 

To  prevent  the  fluid  running  off  from  the  cooler  from  being 


Fig.  74 


Fig  7o 


forced  by  fits  and  starts  from  the  lower  pipe  by  the  current  of 
gas,  the  contrivance  shown  in  Fig.  75  may  be  used.  The  pipe 
D,  coming  from  the  cooling  apparatus,  is  cut  off  at  an  acute 
angle,  and  extends  nearly  to  the  bottom  of  a  cylindrical  vessel 
C,  to  which  is  fixed  a  U-pipe  R  at  such  a  height  that  the  fluid 
in  C  can  rise  to  the  upper  edge  of  the  cut  end  of  D.  The  pipe 
G,  fixed  in  the  lid  of  the  cylinder,  carries  away  the  gas  from  C.' 
Since  with  an  increase  in  the  development  of  gas,  the  latter,  in 
order  to  escape,  needs  only  to  press  down  a  layer  of  liquid  of 
very  moderate  height,  it  can  pass  off  without  impediment, 
while  the  distillate  which  collects  in  C  runs  off  through  R. 


278  MANUFACTURE    OF    VINEGAR. 

If  neither  liquid  nor  gas  escapes  through  D,  the  discharge  of 
wood-vinegar  from  R  ceases  at  once,  and  the  uiouth  of  D  is 
•closed. 

Box-cooler. — In  place  of  the  counter-current  cooler,  the  box- 
cooler  shown  in  Fig.  76  is  used  in  some  establishments.  In  a 
long,  narrow  trough  or  box  of  wrought-iron  or  wood  lies  a 
series  of  straight,  wide,  copper  pipes  with  a  gradually  decreas- 
ing diameter.  The  pipes  are  slightly  inclined,  so  that  the  fluid, 
running  in  at  the  highest  point,  flows  out  at  the  lowest.  Out- 
side the  trough  the  pipes  are  connected  by  movable  elbow 
joints.  One  end  of  each  pipe  is  firmly  fixed  to  the  wall  of  the 
trough,  while  the  other,  to  prevent  free  expansion,  sits  loosely 

FIG.  76. 


in  a  slightly  conical  socket.  The  lower  end  of  the  last  pipe 
divides  into  two  branches,  one  of  them  leading  downward  and 
dipping  into  the  receiver,  while  the  other,  as  a  rule,  conducts 
the  gases  directly  under  the  fireplace.  There  should  be  but  a 
small  space  between  the  collecting  pipe  a,  which  conducts  the 
vapors  to  the  condenser,  and  the  first  condensing  pipe,  as 
otherwise  obstructions  might  readily  be  formed  by  the  deposit 
of  tar  dried  by  the  hot  vapors.  A  constant  stream  of  water  is 
conducted  through  b,  along  the  bottom  of  the  trough,  the 
heated  water  running  off  at  c. 

The  development  of  gas  from  the  wood  being  very  irregular 
and  by  no  means  in  the  proportion  desirable  for  the  heating 
of  the  retorts,  it  is  preferable  to  collect  it  in  a  gasometer  and 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS.  279 

distribute  it  from  there  as  may  be  necessary,  instead  of  con- 
ducting it  directly  into  the  fire.  But  little  gas  is  developed  in 
the  beginning  of  the  operation,  and  much  towards  the  end, 
while  the  reverse  proportion  is  desirable. 

In  case  condensation  is  not  very  complete,  the  pipe  leading 
to  the  hearth  or  gasometer  is  more  or  less  attacked  by  acetic 
acid  precipitated  in  it  by  the  access  of  air.  To  prevent  this 
evil  it  is  advisable  to  place  on  the  pipe  small  receptacles  pro- 
vided with  cocks  for  the  collection  and  discharge  of  any  fluid 
deposited.  These  receptacles  may  also  be  filled  with  quick 
lime,  which  at  least  fixes  the  acetic  acid,  thus  rendering  it 
harmless  for  the  pipe.  The  lime  is  from  time  to  time  extracted 
with  water  to  regain  the  soluble  calcium  acetate. 

To  further  cool  off  the  current  of  gas  and  render  the  vapors 
of  acetic  acid  carried  along  with  it  harmless  for  the  pipe,  Vin- 
cent uses  a  cylindrical  copper  receptacle,  d,  Fig.  76,  provided 
with  a  false  bottom,  upon  which  is  placed  a  layer  of  crystal- 
lized soda  from  2J  to  2J  feet  deep.  The  vapors  of  water  and 
acetic  acid  dissolve  the  soda,  and  the  temperature  thereby 
being  lowered,  a  further  portion  of  the  volatile  bodies,  especi- 
ally wood  spirit,  is  precipitated.  By  distilling  the  fluid  thus 
obtained,  the  wood  spirit  is  regained,  and  the  residue  in  the 
still  used  for  the  preparation  of  sodium  acetate. 

For  a  condenser  for  four  retorts  of  a  capacity  of  141.26 
cubic  feet  each,  Gillot  gives  the  following  approved  dimensions, 
provided  the  period  of  distillation  is  72  hours :  The  diameter 
of  the  pipe  at  its  entrance  into  the  water  trough  is  15}  inches, 
and  at  its  exit  5}  inches ;  its  total  length  is  164  to  180  feet, 
this  length  being  divided  between  6  straight  pieces  and  their 
elbow-joints.  The  vat  is  26J  feet  long  with  a  depth  of  5J 
feet. 

Reservoirs  for  the  Product  of  Distillation. — For  storing  the 
liquid  products  of  the  destructive  distillation  of  wood,  wooden 
vats  6  or  more  feet  high  with  a  capacity  depending  on  the 
quantity  of  the  daily  distillate  are  generally  used,  it  being  ad- 
visable to  have  them  of  such  a  capacity  that  at  least  one  ol 


280 


MANUFACTURE    OF    VINEGAR. 


them  is  filled  every  day.  The  U-pipe  through  which  the  fluids 
run  off  from  the  cooling  apparatus  terminates  over  a  funnel 
fixed  to  a  pipe  which  runs  alongside  the  vats,  and  is  provided 


FIG.  77. 


on  the  corresponding  places  with  stop-cocks  by  means  of  which 
the  fluid  can  be  discharged  into  any  vat  desired. 

Each  vat  is  placed  so  as  to  incline  slightly  forward,  and  on 
the  lowest  place  is  provided  with  a  cock,  beneath  which  is  a 
gutter.  About  8  to  10  inches  above  the  bottom  of  each  vat  is 
a  cock  with  a  gutter  underneath.  Figs.  77  and  78  show  the 
arrangement  of  the  vats.  The  pipe  E  serves  for  filling  the 

FIG.  78. 


vats  with  the  products  of  distillation;  the  cocks  Tand  the 
gutter  Tl  for  discharging  the  tar  into  the  brick  reservoir  H 
sunk  in  the  floor ;  the  cocks  E  and  the  gutter  Ei  for  drawing 


WOOD    VINEGAR    AND    TAR    IN    CLOSED    VESSELS.  281 

off  the  wood  vinegar  into  the  small  vessel  G,  to  which  is- 
secured  the  suction  pipe  /S  of  a  pump  for  the  further  convey- 
ance of  the  wood  vinegar. 

It  is  advisable  to  coat  the  vats  and  iron  hoops  with  hot  wood 
tar. 

Collecting  boxes. — When  working  on  a  large  scale  quite  a 
number  of  vats  are  required,  which  involves  considerable  ex 
pense,  together  with  the  disadvantage  of  occupying  considera- 
ble space.  It  is  therefore  advisable  to  use  in  place  of  vats 
collecting  boxes  sunk  in  the  ground. 

Such  boxes  are  best  and  cheapest  constructed  of  about  3- 
inch  wooden  planks,  every  kind  of  wood  being  suitable  for  the 
purpose,  since  the  products  of  distillation  with  which  the  boxes 
become  saturated  preserves  them  even  in  moist  soil.  From  the 
planks  prismatic  boxes,  each  about  13  feet  long,  13  feet  wide 
and  8  feet  deep  are  constructed.  The  boxes  are  sunk  in  the 
ground,  and  in  the  corner  of  each  box  is  placed  a  small  barrel 
F,  Figs.  79  and  80,  into  which  can  be  dipped  the  suction  pipe 
of  a  pump.  The  spaces  between  the  planks  and  the  walls  of 
the  pit  are  filled  with  earth,  and  the  joints  between  the  planks 
with  pitch.  On  top  each  box  is  provided  with  a  frame,  upon 
which  is  placed  a  lid  made  of  planks. 

The  requisite  number  of  boxes  are  placed  alongside  each 
other  so  that  about  3  feet  of  ground  remain  standing  between 
the  sides  of  every  two  boxes.  The  products  of  distillation  run- 
ning off  from  the  cooling  apparatus  are  conducted  through  a 
pipe  running  the  length  of  the  boxes  into  the  vessel  to  be 
filled.  To  prevent  a  box  from  being  filled  too  full,  all  the 
boxes  are  connected  by  the  wooden  pipe  R,  placed  about  15 
inches  below  the  edge. 

When  a  box  has  been  several  times  filled  with  the  products 
of  distillation,  the  layer  of  tar  deposited  on  the  bottom  is  of 
sufficient  depth  to  be  pumped  out.  The  suction  pipe  of  the 
pump  is  then  lowered  to  the  bottom  of  the  small  barrel  in  the 
corner  of  the  box,  and  the  tar,  with  the  exception  of  a  small 
portion,  can  be  separated  from  the  wood  vinegar  by  pumping. 


MANUFACTURE    OF    VINEGAR. 

Figs.  79  and  80  show  the  arrangement  of  several  such  collect- 
ing boxes  in  ground  plan  and  elevation. 

Since  the  separation  of  the  tar  from  the  wood  vinegar  takes 
place  the  more  completely  the  longer  the  fluids  are  allowed  to 
repose,  it  is  advisable  to  first  fill  all  the  boxes  in  turn  with 
products  of  distillation  and  then  to  work  further  the  contents 
of  the  box  filled  first. 

Utilization  of  the  Gases. — The  gases  evolved  in  the  destructive 
distillation  of  wood  may  advantageously  be  used  as  fuel.  In 
the  commencement  of  the  operation  a  gas  mixture,  very  rich 

FIGS.  79-80. 


in  carbonic  acid,  is  obtained,  which  is  of  little  value  as  fuel, 
but  latter  on  less  carbonic  acid  is  evolved  and  the  gas  contains, 
besides  carbonic  oxide,  hydrogen  and  hydrocarbons,  which  are 
of  considerable  value  as  fuel. 

The  most  suitable  plan  would  be  to  catch  the  gases  by 
means  of  a  pump  from  the  pipe  £,  Fig.  75,  and  collect  them 
in  a  gas  holder  of  ordinary  construction,  and  to  conduct  them 
from  the  latter  by  means  of  pipes  to  the  fire-place.  However, 
a  gasholder  of  sufficient  capacity  to  hold  the  large  quantities 
of  gas  evolved  would  be  rather  an  expensive  affair  for  a  plant 
•engaged  in  the  distillation  of  wood,  and  it  is  therefore  gener- 


DESTKUCTIVE    DISTILLATION    OF    WOOD.  283 

ally  preferred  to  conduct  the  gas  directly  to  the  fire-places 
where  it  is  to  be  burnt. 

When  working  with  a  large  number  of  retorts,  the  operation 
may  be  so  conducted  that  the  wood  or  coal  fire  under  the 
retort  just  placed  in  the  oven  is  allowed  to  go  out  entirely,  and 
to  fire  only  with  gases  escaping  from  retorts  in  which  distilla- 
tion is  in  full  progress,  and  from  which  a  large  quantity  of  gas 
is  constantly  evolved.  In  factories  devoted  to  the  further 
working  of  the  wood  vinegar,  it  is  best  to  conduct  the  gases  of 
distillation  under  an  apparatus  which  has  to  be  heated  almost 
without  interruption,  for  instance,  under  the  pans  in  which 
the  crude  sodium  acetate  is  evaporated  to  crystalization. 

Care  should  be  taken  not  to  ignite  the  gas  escaping  from  the 
retorts  before  all  the  air  has  been  displaced  from  the  entire 
apparatus — retorts,  condenser  and  cooler — since  otherwise  an 
explosion  might  take  place  by  the  flame  spreading  into  the 
pipe  conduit,  which  would  not  only  be  dangerous,  but  suffi- 
ciently heavy  to  tear  apart  the  lute  of  clay  on  the  pipes  for 
the  vapors,  the  condensers,  etc.  When  the  vapors  escaping 
from  a  retort  condense  on  cooling  to  a  yellowish  colored  fluid, 
all  the  air  has  been  displaced  from  the  apparatus,  and  the  gas 
may  be  ignited  without  fear  of  danger. 


CHAPTER  XXIII. 

EXECUTION    OF    THE    DESTRUCTIVE    DISTILLATION    OF    WOOD. 

No  matter  what  the  arrangement  of  the  apparatus  may  be 
in  which  the  destructive  distillation  of  wood  is  to  be  carried 
on,  the  course  of  distillation  as  regards  the  succession  of  phe- 
nomena remains  the  same,  and  a  distinction  has  only  to  be 
made  in  reference  to  the  kind  of  product  desired,  and  the  dura- 
tion of  time  for  the  operation.  The  latter  depends  on  the 
quantity  of  wood  used  at  one  time  ;  the  larger  the  latter  is,  the 


284  MANUFACTURE  OF  VINEGAR. 

longer  the  operation  will  have  to  be  continued,  and  under 
otherwise  equal  conditions,  more  time  will  be  required  for  the 
complete  distillation  of  a  charge  of  wood,  if  wood  vinegar,  tar 
and  black  charcoal  are  to  be  obtained. 

When  working  with  a  larger  number  of  retorts,  the  opera- 
tion should  be  so  arranged  that  it  is  carried  on  uninterrupt- 
edly, this  being  advisable  on  account  of  the  division  of  labor, 
and  also  to  prevent  being  forced  to  adopt  special  expedients 
by  reason  of  the  vast  quantity  of  gas  evolved  at  a  certain  stage 
of  the  operation. 

With  the  use  of  vertical  retorts  and  a  suitable  lifting  tackle, 
the  retorts  are  placed  open  in  the  oven  and  a  gentle  fire  is 
started.  At  first  only  steam  evolves  from  the  wood,  which  is 
allowed  to  escape  into  the  air,  and  only  when  a  peculiar  aro- 
matic odor  indicates  the  commencement  of  distillation,  are  the 
lids  placed  upon  the  retorts  and  connected  with  the  cooling- 
apparatus.  To  make  the  lid  steam-tight,  a  roll  of  clay  is  laid 
upon  the  edge  of  the  retort  and  the  lid  pressed  down  upon  it, 
the  clay  forced  out  thereby  being  smoothed  down  with  an 
elastic  steel  blade. 

The  time  during  which  distillation  has  to  be  continued  de- 
pends on  the  size  of  the  retorts,  but,  as  a  rule,  the  operation 
is  so  conducted  that  distillation  is  finished  in  12  hours.  Of 
course,  with  the  use  of  very  large  apparatus  in  which  a  great 
quantity  of  wood  is  carbonized  at  one  time,  distillation  re- 
quires several  days,  since  the  heating  of  such  a  large  quantity 
of  wood  to  the  temperature  of  decomposition  takes  consider- 
able time.  When  the  temperature — about  393°  F. — has  been 
reached  at  which  the  wood  begins  to  yield  more  abundant 
quantities  of  products  of  distillation,  care  must  be  taken  to 
keep  the  fire  under  the  retorts  so  that  the  temperature  increases 
gradually  and  reaches  662°  F.  only  in  the  last  period  of  dis- 
tillation, so  that  with  a  distilling  time  of  12  hours,  the  tem- 
perature in  the  retorts  remains  for  about  ten  hours  below 
662°  F.  To  gain  practical  experience  in  regulating  the  tem- 
perature in  heating,  which  is  of  special  importance  with  new 


DESTRUCTIVE    DISTILLATION    OF    WOOD.  285 

ovens,  it  is  advisable  to  place  a  thermometer  on  one  of  the  re- 
torts as  follows :  In  a  small  aperture  in  the  lid  of  the  retort 
is  screwed  an  iron  pipe  closed  below  and  open  at  the  top.  The 
length  of  the  pipe  should  be  such  that  the  lower  end  reaches 
to  the  center  of  the  retort.  In  this  pipe  is  lowered  by  means 
of  a  wire  a  thermometer  graduated  to  680°  F.  (the  boiling 
point  of  mercury).  By  from  time  to  time  consulting  this 
thermometer,  a  conclusion  can  be  drawn  as  to  the  degree  of 
heat  prevailing  in  the  retort.  Experienced  men  can  accurately 
judge  of  the  progress  of  distillation  from  the  quantity  of  distil- 
late running  off,  and  of  the  gases  escaping  simultaneously. 

When,  for  instance,  5  cubic  meters  of  wood — the  contents 
of  two  retorts — are  to  be  distilled  at  one  time,  the  first  distil- 
late, in  a  jet  about  the  thickness  of  a  lead  pencil,  is  obtained 
with  correct  firing,  in  about  1 J  to  '2  hours  after  the  commence- 
ment of  heating.  The  thickness  of  the  jet  of  fluid  does  not 
change  for  hours,  and  it  retains  its  original  yellow  color. 
The  gas  issues  in  a  moderately  strong  current  from  the  re- 
spective pipe  and  burns  with  a  pale  blue  flame,  the  latter  be- 
coming more  luminous  only  later  on  at  a  higher  temperature 
when  hydrocarbons  are  mixed  with  the  gas. 

When  a  temperature  of  about  662°  F.  has  been  reached,  the 
quantity  of  distillate  suddenly  becomes  smaller,  and  the  quan- 
tity of  escaping  gas  also  decreases.  In  order  to  obtain  the 
last  remnants  of  the  product  of  distillation,  which  consist  pre- 
dominantly of  tar  products,  the  fire  is  increased,  when  a  more 
abundant  quantity  of  distillate  is  obtained.  However,  the  jet 
of  fluid  running  off  from  the  cooler  is  henceforth  of  nearly  a 
black  color,  due  to  numerous  drops  of  dark-colored  tar  pro- 
ducts. The  volume  of  gas  becomes  larger  and  these  gases 
burn  with  a  very  luminous,  pure  white  flame.  In  this  last 
stage  of  distillation  certain  precautions  have  to  be  observed  in 
reference  to  raising  the  temperature.  If  it  is  raised  too 
rapidly  at  once,  such  a  large  quantity  of  gas  is  evolved  from 
the  retorts  as  to  cause  a  high  pressure  in  the  apparatus,  which 
is  recognized  by  the  force  with  which  the  current  of  gas  issues 


286  MANUFACTURE  OF  VINEGAR. 

from  the  pipe  entering  the  fire-place.  Since  in  this  stage  of 
the  process  the  retorts  are  hottest  and  their  bottoms  not  seldom 
red  hot,  there  is  danger  of  the  riveted  places  becoming  leaky, 
so  that  in  the  succeeding  operations  a  considerable  quantity  of 
products  of  distillation  is  lost  by  'its  escape  in  the  form  of  vapor 
through  these  leaky  places  and  being  burned. 

When  the  volume  of  gas  is  observed  to  becoTne  greater, 
about  1J  hours  before  the  end  of  distillation,  the  fire  under 
the  retort  may  be  allowed  to  go  out  entirely,  since  the  heat 
developed  in  the  retorts  in  consequence  of  decomposition  in 
conjunction  with  that  radiating  from  the  sides  of  the  ovens, 
suffices  to  finish  the  operation.  When  the  temperature  in  the 
retorts  rises  to  806°  F.,  the  evolution  of  products  of  distillation 
ceases  almost  suddenly  and  the  retorts  now  contain  only  black 
charcoal. 

Since  antimony  melts  at  809.7°  F.,  this  metal  may  be  used 
for  determining  the  commencement  of  the  end  of  distillation. 
For  this  purpose  the  thermometer  is  removed  from  the  pipe 
previously  mentioned,  and  a  small  crucible  containing  a  piece 
of  antimony  is  lowered  by  means  of  a  wire  into  the  pipe. 
When  the  antimony  is  melted,  distillation  may  be  considered 
finished  and  the  retort  be  at  once  lifted  from  the  oven. 

The  fluid  which  runs  off  during  distilation  is  at  first  wax- 
yellow,  but  later  on  oecornes  of  a  darker  color,  red  brown,  and 
finally  nearly  black,  and  is  quite  turbid.  When  allowed  to  re- 
pose it  separates  into  two — or  perhaps  more  correctly  into 
three — layers,  sharply  separated  one  from  the  other.  The  low- 
est layer  is  tar,  a  thick  fluid  of  a  dark,  generally  pure  black 
color;  the  middle  layer,  which  comprises  the  greater  quantity, 
is  wood  vinegar,  and  is  of  a  red  yellow  or  red  brown  color. 
The  upper  layer  is  again  of  a  dark  color,  and  possesses  the 
properties  of  tar,  but,  as  a  rule,  this  tarry  mass  is  present 
in  such  small  quantities  that  it  even  does  not  cover  the  entire 
surface,  but  swims  upon  it  like  flakes. 

It  is  advisable  to  allow  the  distillates  to  repose  for  a  consid- 
erable time,  the  tar  thereby  separating  more  completely  from 


DESTRUCTIVE    DISTILLATION    OF    WOOD.  287 

the  wood  vinegar,  and  the  latter  is  obtained  as  an  entirely  clear 
red  brown  fluid,  which  can  be  manufactured  into  acetic  acid 
with  greater  facility  than  wood  vinegar  mixed  with  larger 
quantities  of  tar. 

By  giving  the  vats  intended  for  the  reception  of  the  distillate 
such  a  size  that  one  vat  is  filled  by  the  distillate  obtained  in 
one  day,  and  arranging  twelve  such  vats  as  shown  in  Fig.  78 
the  contents  of  the  vat  filled  first  can  be  allowed  to  repose  for 
11  days  before  the  manufacturer  is  forced  to  empty  it  in  order 
to  make  room  for  fresh  distillate.  When  the  wood  vinegar  and 
tar  are  to  be  worked  further  in  the  factory  itself,  the  appara- 
tuses intended  for  this  purpose  should  be  of  such  dimensions 
that  the  quantity  of  wood  vinegar  produced  daily  can  be 
worked  up  at  one  time.  The  quantity  of  tar  being  considera- 
bly smaller  than  that  of  wood  vinegar,  it  is  collected  in  the  res- 
ervoir H,  Fig.  78,  and  larger  quantities  of  it  are  worked  in  one 
operation. 

When  the  liquid  products  of  distillation  are  caught  in  boxes 
sunk  in  the  ground,  described  on  p.  281,  the  operation  may  be 
so  arranged  that  the  distillate  is  allowed  to  run  uniterruptedly 
into  the  first  box  until  it  is  filled  with  tar  to  such  an  extent 
that  not  only  wood  vinegar,  but  also  tar  commences  to  run  off 
through  the  pipe  R,  Figs.  79  and  80.  The  tar  is  then  allowed 
to  repose  for  some  time,  whereby  it  still  better  separates  from 
adhering  wood  vinegar,  and  the  larger  quantity  of  pure  tar 
thus  obtained  is  then  worked  up  at  one  time. 

Experience  has  shown  that  it  is  of  advantage  to  allow  the 
tar  also  to  repose  as  long  as  possible,  it  having  been  observed 
that  if  kept  for  some  time  in  special  reservoirs,  a  permanent 
separation  of  the  products  according  to  their  specific  gravitie& 
takes  place.  On  the  bottom  of  the  reservoir  tar  of  a  very 
viscous  gritty  nature  collects,  which  is  of  such  thick  consist- 
ency that  it  can  scarcely  be  raised  by  a  pump.  The  higher 
layers  of  the  tarry  mass  are  of  thinner  consistency,  the  upper- 
most being  almost  oleaginous,  and  upon  them  floats  a  layer  of 


-288  MANUFACTURE    OF    VINEGAR. 

wood  vinegar,  which  can  from  time  to  time  be  taken  off  and 
worked  together  with  that  drawn  from  the  vats. 

Yield  of  Products. — The  quantities  of  wood  vinegar  and  tar 
which  are  obtained  from  a  given  quantity  of  wood  depends  on 
several  factors,  namely,  on  the  kind  of  wood,  its  content  of 
water,  and  the  manner  in  which  distillation  itself  has  been 
conducted.  Since  these  three  factors  vary  very  much,  it  is 
evident  that  there  must  be  considerable  differences  in  the 
statements  regarding  the  quantities  of  products  of  distillation, 
and  especially  the  quantities  of  acetic  anhydride  and  wood 
.alcohol  which  can  be  obtained  from  crude  wood  vinegar,  be- 
cause by  careless  manipulation  a  large  quantity  of  the  acetic 
&cid  present  in  wood  vinegar  is  lost. 

In  order  to  obtain  accurate  data  regarding  the  quantities  of 
wood  vinegar  and  tar  which  can  be  obtained  from  a  variety 
of  wood  when  working  on  a  large  scale,  it  is  necessary  to  weigh 
the  wood  worked  during  a  certain  time,  to  determine  its  con- 
tent of  water,  to  ascertain  in  a  sample  of  the  wood  vinegar  re- 
sulting from  each  distillation  the  quantity  of  acetic  acid  and 
wood  alcohol,  and  finally  to  accurately  ascertain  the  volume 
of  vinegar.  From  the  results  of  such  a  series  of  tests  and 
from  the  quantities  of  pure  acetic  acid  and  wood  alcohol  fur- 
nished by  the  factory  itself,  it  would  be  possible  to  obtain  re- 
liable data  regarding  the  quantities  of  products  of  distillation 
which  may  be  obtained  from  a  given  variety  of  wood. 

Stolze  has  published  experiments  made  with  the  greatest 
care  to  show  the  amount  and  strength  of  the  products  obtained 
from  the  distillation  of  several  kinds  of  wood.  The  quantity 
of  each  kind  of  wood  submitted  to  destructive  distillation  was 
one  pound,  a  quantity  suitable,  in  most  cases,  to  form  a  prece- 
dent for  the  manufacture  on  a  large  scale.  The  woods  were 
all  collected  at  the  same  time  of  the  year  (towards  the  end  of 
January)  and  only  those  of  nearly  the  same  growth  were 
chosen.  From  Stoltze's  table  the  following  figures  for  the 
most  important  -varieties  of  wood  have  been  calculated  : 


DESTRUCTIVE    DISTILLATION    OF    WOOD. 


289 


** 

Therein 

Wood 

acetic 

Char- 

Gases, 

vinegar, 

anhydride, 

Tar, 

coal, 

cubic 

pounds. 

pounds. 

pounds. 

pounds. 

meters. 

100  pounds  of  birch  
100  pounds  of  beech  

44.9 
44 

8.9 
8.6 

also 

8.6 
9.5 

24.4 
2J.6 

9.8 
10.8 

100  pounds  of  hornbeam. 
100  pounds  of  oak  

42.5 
43 

7.H 

7  7 

i( 

11.1 
9  1 

23.9 
26  1 

10 
10 

100  pounus  of  fir  

423 

4  2 

H 

11  9 

266 

12.5 

The  results  obtained  by   Assmus  in  manufacturing  on  a 
large  scale  are  as  follows : 


100  pounds  of— 

Yield 
wood 
vinegar, 
pounds. 

Which 
yield 
calcium 
acetate, 
pounds. 

Or 
acetic 
an- 
hydride, 
pounds. 

Tar, 
pounds. 

Char- 
coal, 
pounds. 

Crude 
light 
oil, 
pounds. 

Crude 
heavy 
oil, 
pounds. 

Birch  25  to  40  years  old  .... 
Birch-bark,  first  extract 
Birch-bark,  second  extract. 
Oak    

46 
22 
20 
42 

5.2 
0.6 
0.7 
60 

3.9 
0.4 
0.5 
4  5 

8 
30 
20 

8  8 

23.5 

18.5 
22 

27  5  (f\ 

12 
21.6 
12 
0  8 

4.5 
3.0 
4.7 
33 

Fir        

42 

3  2 

2  4 

10  5 

22 

1  3 

5  7 

Pine 

44  5 

3  0 

2  3 

9  5 

22  6 

0  6 

q  c 

According  to  Roth's  experience,  the  trunk-wood  of  birch 
from  60  to  80  years  old  and  grown  upon  a  high  dry  soil  with 
a  limestone  sub-soil  surpasses  the  best  red  beech  in  the  yield 
of  acetic  acid.  He  obtained  from  100  pounds  of  this  kind  of 
wood  dried  at  140°  to  158°  F.,  with  heating  for  48  hours,  at 
a  temperature  not  exceeding  750°  F.,  40  pounds  of  wood  vin- 
egar of  25  per  cent,  acetic  anhydride,  also  2  or  3  per  cent,  of 
tar,  and  30  per  cent,  of  red  charcoal  suitable  for  the  manufac- 
ture of  powder. 

Klar  *  gives  the  following  yields  obtained  with  retorts. 
The  figures  refer  to  anhydrous  wood  of  100  per  cent.,  expressed 
in  per  cents,  by  weight. 


19 


Technologie  der  Holzverkohlung,  1910. 


290 


MANUFACTURE    OF    VINEGAR. 


Calcium 

.Crude 

Charcoal. 

acetate 
of  80  per 

wood  spirit 
of  100  per 

Tar. 

Tar  oil. 

cent. 

cent. 

3 

a 

8 

a  - 

a 

g 

a 

a 

a 

S 

p 

p 

3 

p 

p 

P 

p 

B 

§ 

§ 

1 

a 

a 

a 

a 

a 

a 

9 

| 

X 

B 

x 

oS 

"S 

M 

cS 

q 

| 

g 

S 

i 

M 

i 

S 

3 

g 

a 

a 

S 

33 
35 
33 
36 

28 

28 
33 

10.5 
8 
2.5 
3.6 

8 

2.3 
3 

2.5 
2 
0.42 
0.8 

1.7 

o'.28 
0.6 

6 

7 
20 
12 

5 

'e 

1 

5 

6.'4 

Very  resinous  fir  

European  fir      

Sawdust  from  conifera.  .  .  . 

33 

.. 

3 

0.6 

10 

Olive  kernels  

35 

4 

1.2 

4 

CHAPTER  XXIV. 


TREATMENT  OF  THE  WOOD  VINEGAR. 

Wood  vinegar  in  the  state  it  is  obtained  from  wood  finds  but 
a  limited  application.  Without  further  treatment  it  can  in  a 
crude  state  be  used  only  for  impregnating  wood  or  for  the 
preparation  of  ferric  acetate  (red  liquor),  because  a  portion  of 
the  tar  products  impart  to  it  a  penetrating  empyreumatic  odor 
rendering  its  use  for  other  purposes  impossible.  It  is  also  not 
possible  to  free  the  wood  vinegar  from  these  tar  products  sim- 
ply by  distillation.  By  repeated  rectification  highly  concen- 
trated acetic  acid  remaining  almost  colorless  in  the  air  is  to  be 
sure  finally  obtained,  but  it  has  always  a  more  or  less  empy- 
reumatic odor  which  makes  it  unavailable  for  comestible  pur- 
poses. 

'The  acetic  acid  can,  however,  be  separated  in  a  perfectly 
pure  state  from  the  wood  vinegar,  and  upon  this  is  based  not 
only  the  preparation  on  a  large  scale  of  the  various  acetates, 
but  also,  what  is  perhaps  of  still  greater  importance,  the  pro- 
duction of  absolutely  pure  acetic  acid  suitable  for  comestible 
purposes. 


TREATMENT    OF    THE    WOOD    VINEGAR.  291 

No  matter  how  the  wood-vinegar  is  to  be  used,  it  is  of  great 
importance  to  separate  it  as'  much  as  possible  from  the  tar- 
Freshly  prepared  wood-vinegar  is  a  turbid  red-brown  fluid. 
By  allowing  it  to  stand  quietly  in  a  tall  vessel  a  quite  thick 
layer  of  tar  separates  on  the  bottom,  over  which  stands  the  per- 
fectly clear  wood-vinegar;  a  thin,  oleaginous  layer  of  light  tar 
products  also  floats  sometimes  upon  the  surface  of  the  vinegar. 
As  in  the  further  treatment  of  the  wood-vinegar  the  presence 
of  tar  causes  many  disturbances,  care  must  be  taken  to  sepa- 
rate it  as  much  as  possible  by  mechanical  means,  this  being 
effected  by  allowing  the  products  of  distillation  to  stand  in  the 
vats  for  several  days — the  longer  the  better. 

It  has  been  proposed  to  heat  the  wood  vinegar  by  placing  a 
copper  coil  in  the  vat,  and  thus  effect  a  more  complete  sepa- 
tion  of  vinegar  and  tar.  But  independent  of  the  expense,  the 
result  of  this  treatment  is  less  favorable  than  that  obtained  by 
allowing  the  products  of  distillation  to  stand  for  a  long  time,, 
and  besides,  by  heating  too  much,  a  portion  of  the  readily 
volatile  wood  spirit  .is  evaporated. 

There  are  several  ways  by  which  concentrated  acetic  acid 
can  be  obtained  from  crude  wood-vinegar,  the  one  to  be  selected* 
depending  on  what  the  acetic  acid  is  to  be  used  for.  When  it 
is  to  be  employed  for  the  production  of  acetates  where  a  slight 
empyreumatic  odor  is  not  detrimental,  it  is  best  to  prepare 
from  the  crude  wood-vinegar  distilled  wood-vinegar,  and  work 
the  latter  into  acetates.  Crude  lead  acetate  can,  for  instance, 
be  prepared  in  this  manner. 

If  the  distilled  wood-vinegar  should  be  directly  used  for  the 
preparation  of  the  various  acetates,  salts  would  be  obtained 
which  on  exposure  to  the  air  would  turn  brown  in  consequence 
of  the  oxidation  of  the  tar-products.  However,  the  behavior 
of  some  acetates  in  the  heat  is  made  use  of  to  obtain  from 
them  chemically  pure  acetic  acid.  While  nearly  all  salts  of 
the  organic  acids  are  decomposed  at  a  comparatively  low  tem- 
perature, some  salts  of. acetic  acid  can  without  suffering  decom- 
position be  heated  to  almost  750°  F.  But  at  this  temperature 


292  MANUFACTURE  OF  VINEGAR. 

all  the  tar  products  adhering  to  the  salt  are  completely  vola- 
tilized or  destroyed,  so  that  by  recrystallizing  the  heated  mass, 
salts  are  obtained  which  are  free  from  empyreumatic  substances, 
and  chemically  pure  acetic  acid  can  then  be  made. 

Distilled  wood  vinegar. — Since  crude  wood  vinegar  always 
contains  tar  in  solution  it  is  absolutely  necessary  to  get  rid  of 
it  before  neutralizing  the  vinegar  and  preparing  calcium  ace- 
tate. High-grade  "  grey  acetate  "  can  only  be  produced  from 
wood  vinegar  freed  from  tar,  otherwise  "  brown  acetate"  con- 
taining at  the  utmost  67  per  cent,  calcium  acetate  is  obtained. 
This  separation  is  effected  by  distillation,  the  tar  remaining 
in  the  still. 

For  this  purpose  the  crude  wood  vinegar  is  subjected  to  dis- 
tillation in  a  simple  still  heated  by  steam,  whereby  about  7 
per  cent,  of  tar  remains  in  the  still.  The  distillate,  called  clear 
vinegar,  still  contains  small  quantities  of  volatile  oils.  They 
are  removed  mechanically  by  allowing  the  clear  vinegar  to 
stand,  or  the  latter  is  separated  in  vats  arranged  one  after  the 
other  in  the  manner  of  Florence  flasks. 

Besides  acetic  acid  the  clear  vinegar  contains  wood  spirit,  i.  e. 
a  mixture  of  methyl  alcohol,  methyl  acetate,  aldehyde,  acetone 
and  allyl-alcohol,  and  can  be  separated  from  it  by  repeated 
fractional  distillation,  whereby  the  methyl  acetate,  however, 
passes  over  into  the  woodspirit,  thus  causing  losses  of  acetic 
acid.  It  is,  therefore,  better  to  first  neutralize  the  distilled 
wood  vinegar  with  milk  of  lime,  whereby  the  greater  portion 
of  the  methyl  acetate  is  saponified,  i.  e.  split  into  calcium  ace- 
tate and  methyl  alcohol,  and  then  distil  it.  The  crude  wood 
spirit  is  then  subjected  to  rectification  and  the  solution  of  cal- 
cium acetate  is  evaporated  and  allowed  to  crystallize. 

This  method  is  obviously  inexpedient  in  so  far  that  distilla- 
tion takes  place  twice.  The  heat  used  for  the  first  distillation 
of  the  crude  wood  vinegar  is  therefore  lost.  Proceeding  from 
this  point  of  view,  M.  Klar  has  devised  the  so-called  "three 
still  system".  The  mixture  of  vapors  .appearing  in  the  first 
distillation  of  the  crude  wood  vinegar  is  at  once  conducted 


TREATMENT    OF    THE    WOOD    VINEGAR.  293 

into  milk  of  lime  where  calcium  acetate  which  remains  in 
solution  is  formed  from  the  acetic  acid.  The  vapors  again 
pass  into  a  still  filled  with  milk  of  lime  where  any  acetic  acid 
which  has  been  carried  along  is  fixed.  The  vapors  pass  finally 
into  a  cooler  where  the  wood  spirit  is  condensed.  Since  the 
boiling  point  of  wood  spirit  is  lower  than  that  of  acetic  acid, 
the  former  does  not  pass  over  up  to  the  end  of  the  operation. 
The  cooler  may  therefore  be  previously  disengaged  and  the 
vapors  be  allowed  to  escape  or  be  used  for  other  purposes.  A 
special  advantage  of  this  method  is  the  complete  utilization 
of  the  latent  heat  of  the  vapors  coming  from  the  first  still. 
Moreover  the  milk  of  lime  in  the  second  and  third  stills  gets  to 
boiling  whereby  the  solution  of  calcium  acetate  is  at  the  same 
time  concentrated.  The  milk  of  lime  in  the  still  has  of  course 
to  be  renewed  before  it  is  completely  saturated  with  acetic 
acid.  When  working  according  to  this  method  three  advan- 
tages are  consequently  gained  in  one  operation,  the  crude 
wood  vinegar  is  freed  from  tar,  the  wood  spirit  is  separated  and 
the  solution  of  calcium  acetate  is  concentrated.  A  solution 
of  calcium  acetate  of  20  to  35  per  cent,  is  obtained,  and  a  dis- 
tillate with  about  10  per  cent,  wood  spirit. 

A  great  saving  in  fuel,  steam  and  space  is  effected  by  F.  H. 
Meyer's  system  (German  patent,  193,382)  of  distilling  the 
crude  wood  vinegar  in  multiple  evaporators  in  vacuum.  It 
is  based  upon  the  fact  that  all  fluids  under  a  decreased  air- 
pressure  boil  at  a  lower  temperature.  Hence  if  vapors  with 
a  lower  temperature  than  the  boiling  point  of  the  fluid  to  be 
evaporated  are  at  disposal  for  heating  purposes,  they  may  be 
used  for  distillation  by  correspondingly  decreasing  the  air- 
pressure  over  the  fluid  to  be  evaporated. 

Freshly-prepared  distilled  wood  vinegar  is  a  colorless,  very 
acid  fluid  with  an  empyreumatic  odor.  On  exposure  to  the 
air  it  acquires  a  brown  coloration  in  consequence  of  the  oxi- 
dation of  the  empyreumatic  bodies.  Although  a  number  of 
expedients  have  been  suggested  for  freeing  the  distilled  wood 
vinegar  from  the  empyreumatic  odor  and  taste,  none  of  them 


294  MANUFACTURE    OF    VINEGAR. 

have  answered  the  purpose  so  far  as  to  make  it  possible  to  use 
the  vinegar  for  comestible  purposes.  The  surest  proof  of  the 
inexpediency  of  these  methods  is  found  in  the  fact  that  none 
of  them  has  been  adopted  in  practice,  though  by  direct  con- 
version of  the  distilled  vinegar,  table  vinegar  could  be  pro- 
duced at  a  very  low  price. 

The  distilled  wood  vinegar  may,  however,  be  directly  used 
for  technical  purposes,  for  instance,  in  the  preparation  of  lead 
acetate,  copper  acetate,  etc.  When  it  is  desired  to  obtain  a 
pure  preparation,  precaution  should  be  taken  to  change  the 
receiver  of  the  apparatus  in  which  the  crude  wood  vinegar 
is  distilled  when  about  80  to  85  per  cent,  of  the  total  quantity 
of  vinegar  which  can  be  obtained  has  passed  over,  experience 
having  shown  that  the  last  portions  of  the  distilled  vinegar 
are  far  richer  in  empyreumatic  substances  than  those  passing 
over  first. 

Stolze  has  proposed  several  methods  for  the  purification  of 
wood  vinegar,  the  most  simple  and  cheapest  being  to  add  5 
pounds  of  finely  pulverized  pyrolusite  to  every  100  quarts  of 
vinegar,  keeping  it  at  nearly  a  boiling  heat  for  6  hours,  then 
digesting  it  in  the  same  manner  with  40  pounds  of  freshly 
glowed  charcoal  pulverized  and  sifted  while  hot,  and  finally 
distilling  off  to  dryness  in  a  shallow  cast-iron  still.  But  on 
account  of  its  tediousness  and  the  necessarily  large  consump- 
tion of  fuel,  this  process,  though  frequently  modified,  has  been 
almost  entirely  abandoned. 

According  to  Tereil  and  Chateau,  the  wood-vinegar  is  puri- 
fied by  compounding  it,  according  to  its  more  or  less  dark  color, 
with  10  or  5  per  cent,  of  concentrated  sulphuric  acid,  whereby 
the  greater  portion  of  the  tar  separates  in  24  hours.  By  dis- 
tilling the  decanted  acid  it  is  obtained  almost  colorless,  but  it 
darkens  somewhat  on  exposure  to  the  air,  and  by  saturation 
with  soda  a  slightly  colored  salt  is  obtained  which  can,  how- 
ever, be  discolored  by  a  small  consumption  of  animal  char- 
coal. 

Rothe  employs  a  peculiar  method   for  the  purification  of 


TREATMENT  OF  THE  WOOD  VINEGAR.          295 

wood-vinegar.  The  greater  portion  of  tar  being  separated  by 
standing,  the  wood-vinegar  with  an  addition  of  charcoal  is 
rectified  from  a  copper  still.  The  pale  yellow  watery  wood- 
spirit  is  caught  by  itself,  and  the  succeeding  clear,  but  strong- 
ly empyreumatic,  distillate  is  pumped  into  a  vat,  placed  at  a 
considerable  height,  from  which  it  runs  into  a  purifying  ap- 
paratus. The  latter  consists  of  a  cylindrical  pipe  of  stout  tin- 
plate.  It  is  about  26  feet  high  and  1J  feet  in  diameter,  and 
is  filled  with  pieces  of  coke  about  0.122  cubic  inch  in  size, 
which  rest  upon  a  heavily  tinned  iron  grate  placed  about  1J 
feet  above  the  bottom  of  the  pipe.  Over  this  column  of  coke 
the  wood-vinegar  is  poured  in  an  uninterrupted  fine  spray, 
while  in  the  space  between  the  bottom  and  the  grate  a  slow 
current  of  air  heated  to  104°  F.  is  constantly  blown  in  through 
a  nozzle.  The  empyreumatic  oils  mixed  with  the  wood-vine- 
gar are  oxidized  by  the  oxygen  of  the  warm  air,  and,  in  con- 
sequence, the  temperature  in  the  interior  of  the  column  of 
coke  rises  to  122°  F.,  and  over.  The  pipe  is  protected  from 
cooling  off  by  a  thick  layer  of  felt.  The  products  of  the  oxi- 
dation of  the  empyreumatic  oils  are  partially  of  a  resinous 
nature  and  adhere  to  the  coke,  and  partially  volatile.  The 
acetic  acid  running  off  through  an  S-shaped  pipe  on  the  bot- 
tom of  the  pipe  is  clear,  of  a  pure  acid  taste,  and  suitable  for 
the  preparation  of  all  the  acetates  as  well  as  of  acetic  acid. 
The  very  slight  empyreumatic  odor  disappears  by  forcing  the 
product  through  a  pipe  filled  with  pieces  of  animal  charcoal 
free  from  lime.  The  vinegar  thus  obtained  is  claimed  to  be 
suitable  for  table  use.  Though  a  quantity  of  acetic  acid  is 
carried  off  in  the  form  of  vapor  by  the  warm  dry  current  of 
air,  this  loss  can  be  prevented  by  passing  the  air  through  an- 
other pipe  filled  with  calcined  soda  or  lime. 

Experiments  have  shown  that  the  method  above  described 
cannot  be  recommended  for  practice,  because  by  the  resinous 
oxidation-products  deposits  are  soon  formed  upon  the  pieces 
of  coke  which  obstruct  the  free  passage  of  the  current  of  fluid 
and  air,  necessitating  a  frequent  renewal  of  the  charge  of  coke. 


296  MANUFACTURE    OF    VINEGAR. 

Besides  a  portion  of  the  oxidation-products  remains  dissolved 
in  the  vinegar  itself,  rendering  it  for  this  reason  alone  unfit 
for  table  use. 

The  only  way  to  prepare  perfectly  pure  acetic  acid  from  the 
wood  vinegar  is  to  fix  the  acetic  acid  to  strong  bases,  strongly 
heat  the  resulting  salts  so  that  all  tar  substances  are  volatilized 
or  decomposed,  and  to  separate  from  the  salts  thus  purified 
acetic  acid  by  distillation  with  strong  acids.  According  to  this 
process  crystallized  acetic  acid — the  chemically  pure  prepara- 
tion— can  finally  be  prepared. 

Production  of  pure  acetic  acid  from  wood  vinegar. — The  basic 
bodies  employed  in  the  practice  to  fix  the  acids  contained  in 
wood  vinegar  are,  according  to  the  object  in  view,  either  lime 
or  sodium,  the  former  being  used  for  the  preparation  of  acetic 
acid  suitable  for  technical  purposes,  and  the  latter  for  that  of 
absolutely  pure  acetic  acid  fit  for  comestible  use.  In  many 
plants  not  equipped  with  the  apparatus  required  for  the  pro- 
duction of  pure  acetic  acid,  the  crude  wood  spirit  is  distilled 
off  from  the  wood  vinegar  and  the  residue  in  the  still  used  for 
the  preparation  of  crude  calcium  acetate,  these  two  raw  pro- 
ducts being  sold  to  chemical  factories.  This  course  is  of 
special  advantage  where  the  charges  for  transporting  the 
chemicals  are  very  high,  the  weight  of  the  crude  wood  spirit 
and  that  of  the  crude  calcium  acetate  being  very  likely  scarcely 
10  per  cent,  of  the  weight  of  the  wood  used.  Besides  working 
up  the  calcium  acetate  for  acetone  has  also  to  be  taken  into 
consideration. 

Since  calcium  acetate  aiid  sodium  acetate  are  the  technically 
most  important  salts  of  acetic  acid  their  preparation  will  be 
somewhat  fully  described. 

Preparation  of  calcium  acetate. — For  the  neutralization  of  the 
crude  wood  vinegar  freed  by  distillation  from  wood  spirit, 
burnt  and  slaked  lime  is  generally  used,  though  as  acetic  acid 
is  a  strong  acid  and  can  with  ease  displace  carbonic  acid  from 
salts,  lime  stone  i.  e.  carbonate  of  lime  may  also  be  employed 
for  the  purpose.  The  limestone  must,  however,  be  quite  pure, 


TREATMENT  OF  THE  WOOD  VINEGAR.          297 

especially  as  free  as  possible  from  organic  substances,  and' 
neutralization  has  to  be  effected  in  large  vessels,  as  the  calcium 
acetate  solution  foams  very  much  in  consequence  of  the  escaping 
carbonic  acid  ;  this  drawback  is  avoided  with  the  use  of  burnt 
lime. 

The  neutralized  fluid  should  be  allowed  to  stand  several 
days  so  that  the  tarry  substances  contained  in  the  wood  vinegar 
can  collect  on  the  surface  and  be  removed.  It  is  of  importance 
to  only  just  neutralize  the  wood  vinegar  with  lime  and  not 
use  lime  in  excess,  because  then  a  portion  of  the  acid  tar- 
products  passes  already  into  the  layer  of  tar  collecting  on  the 
surface  and  can  be  separated  together  with  it  from  the  calcium 
acetate  solution.  When  this  has  been  done  the  solution  is 
mixed  with  1 J  to  1 J  per  cent,  by  volume  of  crude  hydrochloric 
acid  and  allowed  to  rest.  The  mass  which  thereby  separates 
on  the  surface  consist  chiefly  of  those  substances  in  which  creo- 
sote occurs.  It  is  collected  and  worked  by  itself  for  creosote. 

The  clear  calcium  acetate  solution  is  evaporated  in  shallow 
iron  pans,  which  may  be  heated  by  the  fire  gases  escaping 
from  the  retort  ovens.  The  tarry  substances  which  separate 
during  evaporation  in  the  form  of  pitch-like  masses  are  care- 
fully removed.  Evaporation-  is  continued  till  the  specific 
gravity  of  the  hot  fluid  is  =  1.116  or  15°  Be.  When  this 
point  has  been  reached,  the  boiling  hot,  highly  concentrated 
solution  of  the  salt  commences,  on  being  further  evaporated, 
to  separate  crusts  of  salt.  These  crusts  are  removed  and  com- 
pletely dried  in  smaller  pans,  whilst  being  constantly  stirred. 
In  plants  having  power 'at  their  disposal,  evaporation  and 
drying  can  be  effected  in  one  vessel,  a  circular  pan  in  which 
a  stirrer  moves  uninterruptedly  being  used  in  this  case. 
When,  as  previously  mentioned,  the  fire  gases  escaping  from 
the  retort  ovens  are  utilized  for  heating  the  evaporating  pans, 
there  is  no  danger  of  the  decomposition  of  the  calcium  acetate 
by  overheating  of  the  salt  mass,  since  by  simply  pushing  a 
slide  the  fire  gases  can  be  immediately  given  another  direc- 
tion. Overheating  of  the  mass  in  drying  is  indicated  by  the 


298  MANUFACTURE  OF  VINEGAR. 

•characteristic  odor  of  acetone.  '  While  calcium  acetate  is  de- 
com posed  at  between  426°  and  428°  F.,  acetone  being  evolved 
and  carbonate  of  lime  remaining  behind,  the  process  com- 
mences already  at  about  302°  F. 

It  is  most  expedient  to  evaporate  the  calcium  acetate  solu- 
tion only  to  a  doughy  mass  which  can  be  lifted  out  with  a 
shovel,  and  to  effect  the  complete  drying  of  this  mass  upon 
iron  plates  forming  the  bottom  of  a  flat  arch  and  heated  by 
the  fire  gases  escaping  from  the  retort  ovens.  The  tempera- 
ture in  the  arches  should  be  so  regulated  as  to  never  exceed 
302°  F.,  but  the  crude  salt  should  be  exposed  for  several  hours 
to  this  temperature,  because  by  long-continued  heating  at  a 
lower  temperature  a  great  many  more  tarry  substances  are 
destroyed  and  volatilized  than  by  stronger  heating  for  a 
shorter  tim.e,  which  besides  is  accompanied  by  the  danger  of 
decomposing  a  portion  of  the  calcium  acetate. 

In  heating  the  evaporating  pans  by  a  direct  fire  there  is 
always  danger  of  overheating.  Besides,  the  pans  soon  become 
covered  with  a  crust  of  calcium  acetate,  which  renders  the 
transmission  of  the  heat  very  difficult.  For  this  reason  round 
or  square  pans  heated  by  steam  are  as  a  rule  used  in  large 
modern  plants.  These  pans  have  a  double  bottom  into  which 
steam  is  conducted.  Copper  pans  are  preferable  to  iron  ones, 
since  the  acetate  burning  to  the  pans  can  be  more  readily  re- 
moved from  copper.  The  use  of  such  pans  is,  however,  only 
advisable  for  the  evaporation  of  solutions  already  concen- 
trated. For  dilute  solutions  it  is  better  to  first  concentrate 
them  in  multiple  evaporators  in  vacuum,  F.  H.  Meyer's  sys- 
tem, German  patent  193,382,  previously  referred  to.  In  this 
apparatus  the  solution  is  brought  to  30  to  35  per  cent,  dry 
substance  and  then  transferred  to  the  open  pans  mentioned 
-above. 

To  avoid  the  tedious  and  disagreeable  work  of  completely 
evaporating  and  drying  the  calcium  acetate  in  pans,  M.  Klar 
has  devised  a  continuously-working  apparatus.  It  consists  of 
a.  revolving  hollow  iron  cylinder  heated  inside  by  steam  or 


TREATMENT    OF    THE    WOOD    VINEGAR.  299 

waste  gases.  In  revolving,  the  heated  cylinder  dips  into  the 
•calcium  acetate  solution  and  becomes  coated  with  a  thin  layer 
of  it,  which  dries  quickly  and  is  removed  by  scrapers.  With 
this  apparatus  gray  acetate  with  80  per  cent,  can  be  prepared 
from  acetate  solution  in  one  uninterrupted  operation.  Since, 
however,  the  acetate  is  obtained  in  the  form  of  a  fine,  light 
powder,  Klar  carries  on  the  drying  process  only  far  enough  to 
-obtain  a  product  which  is  no  longer  sticky.  This  is  dried  in 
a  closed  band  heated  by  warm  air,  and  at  the  same  time 
granulated. 

The  crude  gray  acetate  thus  obtained  forms  a  gray  odorless 
mass.  It  consists  of  about  80  per  cent,  calcium  acetate  and 
is  a  commercial  article.  In  addition  to  calcium  acetate  it 
contains  calcium  butyrate  and  propionate,  as  well  as  certain 
empyreumatic  bodies,  and  the  acetic  acid  prepared  from  it 
also  contains  butyric  acid,  propionic  acid,  etc.  Hence  this 
acetic  acid  cannot  be  directly  used  for  comestible  purposes, 
but  is  suitable  for  most  technical  uses.  Calcium  acetate  is 
largely  used  in  print  works  and  in  dyeing,  and  also  serves  for 
the  preparation  of  acetone. 

Preparation  of  Sodium  Acetate. — Sodium  acetate  in  a  pure  state 
can  be  obtained  according  to  several  methods  which,  however, 
differ  from  each  other  only  in  a  certain  stage  of  the  operation, 
the  latter  beginning  always  with  the  neutralization  of  the  wood 
vinegar  freed  from  wood  spirit.  For  this  purpose  sodium  car- 
bonate is  preferably  used,  as  crystallized  soda,  in  consequence 
of  its  content  of  water  of  crystallization,  entails  high  charges 
for  transport. 

Neutralization  is  effected  by  adding  gradually  the  sodium 
carbonate  to  the  wood  vinegar,  as  otherwise  the  escaping  car- 
bonic acid  causes  strong  foaming  and  the  fluid  would  run  over 
even  with  the  use  of  a  very  tall  vessel.  Enough  soda  should 
be  added  to  the  wood  vinegar  for  the  fluid  to  contain  a  very 
small  excess  of  sodium  carbonate,  because  the  sodium  acetate 
crystallizes  with  greater  ease  from  a  slightly  alkaline  fluid 
than  from  a  perfectly  neutral  one. 


300  MANUFACTURE  OF  VINEGAR. 

After  adding  the  soda  the  fluid  is  allowed  to  rest  for  one 
day  for  the  separation  of  the  tarry  substances,  and  after  remov- 
ing the  latter,  the  fluid  is  evaporated  in  shallow  pans,  which 
are  heated  by  the  fire  gases  escaping  from  the  retort  ovens  or 
over  an  open  fire.  Evaporation  is  continued  until  the  hot 
fluid  shows  a  specific  gravity  of  1.23  =  27°  Be.  The  fluid  is 
then  emptied  into  the  crystallizing  boxes,  in  which,  after  the 
separation  of  the  crystals  of  crude  sodium  acetate,  remains  the 
mother-lye.  The  latter  is  returned  to  the  evaporating  pans. 

The  mother-lye  is  at  the  ordinary  temperature  a  saturated 
solution  of  sodium  acetate,  mixed,  however,  with  the  bulk  of 
sodium  butyrate  and  sodium  propionate  contained  in  the 
wood  vinegar  used.  When  these  mother-lyes  are  continually 
returned  to  the  evaporating  pans,  the  quantity  of  sodium  buty- 
rate and  sodium  propionate  finally  accumulates  to  such  an 
extent  that  in  cooling  the  fluid  evaporated  to  specific  gravity 
1.23,  a  granular  crystal  mass  is  no  longer  formed,  but  a  soft 
paste  is  separated.  In  this  case  the  fluid  in  the  pans  has  to  be 
entirely  removed  and  treated  as  will  be  described  later  on. 

It  is  of  great  importance  as  regards  the  purification  of  the 
crude  crystals  to  cool  the  evaporated  fluid  very  rapidly  in 
order  to  obtain  small  crystals  which  retain  but  little  mother- 
lye.  For  this  purpose  oblong  sheet-iron  crystallizing  pans 
with  slightly  inclined  sides  are  used.  When  the  contents  of 
the  crystallizing  vessels  have  cooled  to  the  ordinary  tempera- 
ture, they  form  a  dark-colored  paste  of  crystals  which  holds 
the  entire  quantity  of  mother-lye. 

To  separate  the  crystals  as  completely  as  possible  from 
mother-lye  one  of  two  methods  may  be  adopted,  namely, 
draining  and  washing,  or  by  means  of  a  centrifugal.  Accord- 
ing to  the  first  method  the  crystallizing  pans  are  placed  in  a 
slanting  position,  whereby  a  great  portion  of  the  mother-lye 
runs  off  and  is  returned  to  the  evaporating  pans.  The  mass  of 
crystals  is  brought  into  a  vat  with  a  false  bottom,  below  which 
is  a  discharge  pipe.  When  the  vat  is  filled  with  the  mass  of 
crystals,  water  is  poured  in.  The  water  dissolves  a  certain 


TREATMENT    OF    THE    WOOD    VINEGAR. 


301 


Fig.  81 


quantity  of  sodium  acetate,  and  this  solution  in  sinking  down 
displaces  the  mother-lye,  a  salt  of  a  quite  pale  brown  color 
remaining  behind. 

However,  as  this  method  requires  considerable  time  and 
leaves  the  salt  in  a  wet  state,  it  is  preferable  to  free  the  salt 
from  the  mother-lye  by  means  of  a  centrifugal,  it  being  then 
obtained  perfectly  dry.  In  distilling  this  salt  with  sulphuric 
acid,  an  acid  is  obtained  which  to  be  sure  is  still  empyreu- 
matic,  but  which  can  be  directly  used  for  many  manufacturing 
purposes. 

To  obtain  pure  sodium  acetate,  the  crude  salt  is  dissolved  in 
water  by  means  of  steam  so  that  a  nearly  boiling  solution  of 
15°  Be.  is  obtained,  which  is  then  filtered  in  a  hot  state  through 
animal  charcoal  in  a  filter  which  can  be  heated.  The  filter, 
Fig.  81,  consists  of  an  iron  cylinder,  C,  10  to  13  feet  high,  en- 
closed in  a  somewhat  larger  iron  cylin- 
der C.  The  inner  cylinder  is  filled  with 
granulated  animal  charcoal,  and  steam 
circulates  in  the  space  between  the  two 
cylinders.  To  avoid  the  necessity  of 
charging  a  filter  in  too  short  a  time 
with  fresh  animal  charcoal,  four  to  six 
of  such  filters  are  arranged  in  a  battery. 
When  the  first  filter  becomes  ineffec- 
tual, it  is  emptied,  charged  with  fresh 
animal  charcoal  and  placed  as  the  last 
in  the  battery.  Filtration  of  the  hot 
solution  should  progress  only  with  such 
rapidity  that  a  colorless  fluid  runs  off 
from  the  last  filter.  This  fluid  when 
rapidly  cooled  deposits  small  colorless 
crystals  which  after  having  been  freed  from  mother-lye  by 
means  of  a  centrifugal  and  dried,  pass  in  commerce  as  pure  so- 
dium acetate. 

However,  even  to   the  salt  purified  in  this  manner  adhere 
certain,  though  only  very  small  quantities,  of  sodium  butyrate 


302  MANUFACTURE  OF  VINEGAR. 

and  sodium  propionate,  and  the  acetic  acid  prepared  from  it 
contains  the  corresponding  quantities  of  butyric  and  propionic 
acids.  The  odor  of  butyric  acid  is,  however,  so  penetrating 
that  its  presence  in  the  acetic  acid  can  be  immediately  detec- 
ted by  the  sense  of  smell.  By  rubbing  such  impure  acetic 
acid  upon  the  palm  of  the  hand,  the  disagreeable  odor  of 
butyric  acid  becomes  conspicuous  as  soon  as  the  more  volatile 
acetic  acid  has  evaporated. 

Hence  for  the  preparation  of  perfectly  pure  acetic  acid  such 
as  is  demanded  for  comestible  purposes,  a  different  course  ha& 
to  be  adopted  which  to  be  sure  is  somewhat  more  troublesome 
than  the  previously  described  process  but  surely  accomplishes 

Fig.  82. 


the  object  in  view.  It  is  based  upon  the  fact  that  sodium  ace- 
tate may  be  heated  to  nearly  752°  F.  without  suffering  decom- 
position, while  sodium  butyrate  and  sodium  propionate  are 
decomposed  and  the  tarry  substances  volatilized  at  a  considera- 
bly lower  temperature. 

The  salt  obtained  from  the  first  crystallization  purified  by 
washing  or  by  means  of  a  centrifugal  is  used  for  this  purpose. 
It  is  melted  in  a  cast-iron  boiler,  Fig.  82,  about  5  feet  in  di- 
ameter and  about  8  inches  deep,  equipped  with  a  stirrer 
furnished  with  two  curved  blades.  The  salt  at  first  melts 
very  rapidly  in  its  water  of  crystallization,  yielding  the  latter 
with  heavy  foaming,  so  that  finally  a  crumbly  yellow-brown 


TREATMENT    OF    THE    WOOD    VINEGAR.  303 

mass  remains  behind  which  constantly  emits  tar  vapors.  The 
fire  under  the  kettle  is  kept  up  uniformly  for  about  one  hour 
and  is  only  sufficiently  increased  for  the  mass  to  melt  when 
no  more  vapors  rise  from  the  latter.  The  melted  mass  is  lifted 
from  the  kettle  with  shallow  shovels  and  poured  upon  sheet- 
iron  plates  where  it  congeals  to  a  gray-white  cake  full  of  small 
blisters. 

When  the  operation  above  described  has  been  correctly 
carried  on,  the  congealed  melt  contains  sodium  acetate,  car- 
bonaceous matter  and  such  a  small  quantity  of  tarry  substances 
that,  when  brought  into  water,  it  yields  a  solution  of  a  very 
pale  yellow  color.  If  the  heat  has  been  raised  too  high,  a 
portion  of  the  sodium  acetate  is  also  decomposed,  acetone  being 
evolved  and  soda  remaining  behind.  It  may  sometimes 
happen  that  the  whole  mass  takes  fire  ;  the  latter  is  extin- 
guished by  throwing  crude  crystals  upon  it. 

The  melted  mass  is  dissolved  in  boiling  water.  The  boiling 
hot  solution,  which  is  colored  dark  by  suspended  particles  of" 
carbonaceous  matter,  is  filtered  through  a  filter  filled  with 
sand  and  heated  by  steam,  and  then  quickly  cooled  in  order 
to  obtain  small  crystals  which  after  treatment  in  a  centrifugal 
should  be  perfectly  colorless.  Since  it  is  next  to  impossible 
to  heat  every  portion  of  the  melting  mass  exactly  so  long 
until  all  the  coloring  matters  have  been  destroyed,  solutions- 
of  a  yellow  color  yielding  yellow  crystals  are  sometimes  ob- 
tained. By  redissolving  these  yellow  crystals  in  boiling  water 
and  passing  the  solution  through  an  animal  charcoal  filter 
entirely  colorless  crystals  are  also  obtained. 

The  sodium  acetate  thus  obtained  forms  colorless  crystals  of 
the  composition  NaC2H302-f  3H2O,  which  effloresce  on  exposure 
to  the  air.  At  the  ordinary  temperature  the  salt  dissolves  in 
about  three  times  its  quantity  by  weight  of  water.  With  an 
increasing  temperature,  its  solubility  becomes  much  greater 
and  the  saturated  solution,  boiling  at  255.2°  F.,  contains  for 
100  parts  of  water  208  parts  of  the  salt.  When  heated  the 
salt  melts  at  172.4°  F.,  yields  its  water  of  crystallization,  and; 


304  MANUFACTURE    OF    VINEGAR. 

•congeals.  It  then  melts  again  only  at  606.2°  F.,  and  in  a 
melted  state  can  be  heated  to  between  716°  and  752°  F.,  with- 
out suffering  decomposition.  When  heated  above  this  tem- 
perature it  evolves  acetone,  becomes  readily  ignited  in  the  air, 
and  finally  leaves  a  residue  consisting  of  sodium  carbonate 
and  coal. 

The  mother-lyes  which  in  the  course  of  time  accumulate  in 
the  pan  and  finally  no  longer  crystallize  are  evaporated  to  the 
•consistency  of  syrup  and  stored  in  vats.  In  a  few  weeks  they 
are  separated  from  the  crude  salt  and  further  worked.  In 
most  plants  this  is  done  by  evaporating  the  lye  to  dry  ness  and 
incinerating  the  residue  whereby  calcium  carbonate  mixed 
with  coal  remains  behind,  which  is  again  used  for  the  neutra- 
lization of  wood  vinegar. 

When  100  parts  of  the  strongly  inspissated  lye  are  mixed 
with  20  parts  by  weight  of  strong  alcohol  and  70  parts  by 
by  weight  of  sulphuric  acid  are  gradually  added,  a  black,  oily 
layer  separates  on  the  surface  of  the  fluid.  This  layer  con- 
sists of  crude  acetic,  butyric  and  propionic  ethers  besides 
small  quantities  of  formic,  valeric  and  capric  ethers  and  from 
these  raw  products  all  the  mentioned  acids  can  be  prepared  in 
a  pure  state. 

The  purification  of  the  sodium  acetate  by  filtration  through 
animal  charcoal  is  at  present  only  seldom  practised,  the  melt- 
ing process  being  more  simple  to  manipulate  and  yielding 
better  results. 

Sodium  acetate  can  also  be  prepared  from  calcium  acetate 
by  transposition  with  a  soluble  sodium  salt,  the  acid  of  which 
forms  with  the  calcium  an  insoluble  combination.  By  mixing, 
for  instance,  a  solution  of  calcium  acetate  with  one  of  sodium 
sulphate  (Glauber's  salt),  insoluble  calcium  sulphate  is  formed 
and  sodium  acetate  remains  in  solution.  The  calcium 
sulphate  (gypsum)  is,  however,  not  entirely  insoluble  and  it  is 
therefore  far  better  to  effect  transposition  with  the  use  of 
sodium  carbonate  whereby  calcium  carbonate  dissolving  with 
greater  difficulty  is  formed. 


TREATMENT    OF    THE    WOOD    VINEGAR.  305 

Preparation  of  acetic  acid  from  the  acetates. — For  the  prepara- 
tion of  acetic  acid  in  a  free  state  the  calcium  acetate  is  decom- 
posed by  an  acid  and  the  acetic  acid  separated  by  distillation. 
Hydrochloric  acid  was  formerly  generally  used  for  the  purpose? 
it  having  the  advantage  of  forming  with  the  calcium,  calcium 
chloride  which  is  readily  soluble  in  water  and  in  distilling  pre- 
sents fewer  obstacles  than  the  calcium  sulphate  (gypsum) 
formed  by  the  decomposition  of  the  acetate  with  sulphuric  acid, 
but  the  latter  is  now  almost  exclusively  used,  this  process  being 
preferable  because,  on  the  one  hand,  the  apparatus  required 
for  it  has  been  greatly  improved  and,  on  the  other,  the  gray 
acetate  with  80  to  82  per  cent,  acetate  furnishes  a  better  and 
purer  raw  material.  The  further  manipulation  of  the  acetic 
acid  is  then  effected  in  a  distilling  column  which  renders  it 
possible  to  prepare  at  once  from  the  crude  acid,  perfectly  pure 
acetid  acid  and  also  glacial  acetic  acid. 

Hydrochloric  Acid  Process. — The  decomposition  of  the  cal- 
cium acetate  may  be  effected  by  aqueous,  as  well  as  by  gaseous 
hydrochloric  acid.  As  previously  mentioned,  the  hydrochloric 
acid  process  has  been  generally  abandoned,  it  being  now  in 
use  only  where  brown  acetate  with  about  67  per  cent,  acetate 
is  to  be  worked.  This  product  being  far  more  impure  is  for 
that  reason  not  suitable  for  decomposition  with  sulphuric  acid, 
because  the  resinous  and  tarry  substances  which  are  present 
in  abundance  exert  a  reducing  action  upon  the  sulphuric 
acid. 

The  quantity  of  calcium  acetate  to  be  treated  is  brought  in- 
to a  vat  and  after  pouring  the  requisite  quantity  of  hydro- 
chloric acid  over  it,  the  mass  is  thoroughly  stirred  and  then 
allowed  to  rest  for  24  hours.  During  this  time  it  liquifies  and 
tarry  substances  separate  on  the  surface.  These  substances 
have  to  be  carefully  removed  before  bringing  the  contents  of 
the  vat  into  a  still. 

The  quantity  of  hydrochloric  acid  required  for  the  decom- 
position of  the  calcium  acetate  could  ver}^  readily  be  accurately 
determined  if  the  combinations  contained  in  the  salt,  which  are 
20 


306  MANUFACTURE    OF    VINEGAR. 

decomposed  by  hydrochloric  acid,  were  exactly  known.  But 
this  can  only  be  learned  from  a  complete  analysis  of  a  sample 
of  the  calcium  acetate.  However,  in  the  practice  this  trouble- 
some work  is  generally  avoided  and  the  required  quantity  of 
hydrochloric  acid  is  determined  by  pulverizing  a  portion  of 
the  calcium  acetate  and,  after  adding  to  every  100  grammes  of 
salt  90  or  95  grammes  of  hydrochloric  acid,  distilling  the  mass 
in  a  small  glass  still.  The  distillate  is  tested  for  the  presence 
of  hydrochloric  acid  by  the  addition  of  solution  of  nitrate  of 
silver.  If  after  a  short  time  the  fluid  commences  to  opalesce 
or  a  caseous  precipitate  is  formed  in  it,  hydrochloric  acid  is 
present. 

A  content  of  hydrochloric  acid  renders  the  acetic  acid  un- 
suitable for  many  purposes,  and,  hence,  the  use  of  a  small  ex- 
cess of  calcium  acetate  is  advisable.  When  the  operation  is 
carefully  conducted  and  especially  too  rapid  distillation  con- 
nected with  squirting  of  the  mass  avoided,  the  acetic  acid  then 
obtained  contains  only  traces  of  hydrochloric  acid,  and  can  be 
freed  from  them  by  rectification  over  some  calcium  acetate. 
With  the  use  of  crude  hydrochloric  acid  of  1.16  specific  gravity, 
an  acid  is  obtained  from  the  calcium  acetate  which  contains 
between  47  and  50  per  cent  of  acetic  anhydride,  and  possesses 
a  yellowish  color  and  a  slightly  empyreumatic  odor  and  taste. 

Distillation  is  effected  in  a  copper  still  which  is  protected 
from  the  direct  action  of  the  fire  by  an  iron  shell.  The  worm 
may  be  made  of  lead  and  should  below  be  furnished  with  a 
U-shaped  piece  which,  when  distillation  begins,  becomes 
immediately  filled  with  acetic  acid  and  prevents  the  entrance 
of  air  into  the  worm.  By  thoroughly  washing  the  worm  with 
water  after  each  distillation  it  is  not  attacked  by  the  acetic 
acid,  or  only  so  slightly  that  the  quantity  of  lead  which  by 
these  means  reaches  the  acetic  acid  is  insignificant  in  a  product 
intended  for  technical  purposes. 

If  rectification  of  the  acetic  acid  is  effected  over  potassium 
dichromate  instead  of  over  calcium  acetate,  an  acid  is  to  be 
sure  obtained  which  contains  no  hydrochloric  acid  and  is 


TREATMENT    OF    THE    WOOD    VINEGAR.  307 

colorless,  but  has  still  a  very  perceptible  empyreumatic  taste. 
Since  potassium  dichromate,  1  to  1J  Ibs.  of  which -has  to  be 
used  for  every  100  Ibs.  of  acid,  is  quite  expensive,  its  use  for 
the  preparation  of  acetic  acid  from  calcium  acetate  cannot  be 
recommended,  since  the  resulting  acetic  acid,  on  account  of 
its  empyreumatic  taste,  cannot  be  used  for  comestible  purposes. 

The  decomposition  of  the  acetate  can,  as  previously  men- 
tioned, be  also  effected  with  gaseous  hydrochloric  acid,  the 
advantage  of  this  process  being  that  concentrated  acetic  acid 
is  at  once  obtained.  The  operation  is  carried  on  by  bringing 
a  sufficient  quantity  of  finely  pulverized  calcium  acetate  into 
vertical  retorts  which  can  be  heated  from  the  outside.  Gaseous 
hydrochloric  acid,  previously  heated,  is  conducted  through 
the  retorts  and  the  escaping  vapors  of  acetic  acid  are  condensed. 
However,  with  the  use  of  this  process,  the  crude  acetic  acid 
obtained  is  very  much  contaminated  with  hydrochloric  acid, 
especially  towards  the  end  of  the  operation  when  the  greater 
portion  of  the  calcium  acetate  has  already  been  decomposed. 

Sulphuric  acid  process. — At  present  the  decomposition  of  the 
calcium  acetate  is,  as  previously  mentioned,  almost  exclusively 
effected  with  sulphuric  acid,  insoluble  calcium  sulphate  being 
separated  which  forms  a  viscid,  pasty  mass,  and  finally 
becomes  solid.  In  order  to  attain  complete  decomposition  the 
mass  has  to  be  thoroughly  shaken,  a  work  which  requires 
considerable  expenditure  of  power.  Gypsum  is  a  bad  conduc- 
tor of  heat,  and  although  heat  is  liberated  during  the  progress 
of  the  reaction  itself  whereby  a  portion  of  the  acetic  acid 
evaporates,  to  obtain  the  last  remnants  of  acetic  acid  which 
are  tenaciously  held  by  the  gypsum,  is  connected  with  diffi- 
culties. With  the  use  of  higher  temperatures  than  attainable 
with  direct  firing  the  mass  can  to  be  sure  be  so  far  heated  that 
all  the  acetic  acid  finally  passes  over,  but  a  heavy  reduction 
of  sulphuric  acid  then  also  takes  place.  For  this  reason  the 
more  modern  processes  work  with  the  use  of  a  vacuum  and 
steam  for  heating,  far  better  yields  and  a  purer  acid  being 
thereby  obtained. 


308  MANUFACTURE    OF    VINEGAR. 

Below  a  description  of  an  older  plant  arranged  according 
to  Biihler  for  the  sulphuric  acid  process  will  first  be  given, 
IFig.  83  a  to  d. 

:From  the  lime  kiln  the  roasted  calcium  acetate  is  directly 
'thrown  through  the  funnel  o  into  the  storage  receptacle  p, 
which  serves  also  as  a  measuring  vessel  for  one  charge.  De- 
•composition  is  effected  in  shallow  cast-iron  pans  a,  equipped 
•with  stirrers,  and  the  covers  of  which  are  furnished  with  man- 
liole,  exhaust  pipe,  safety  valve  and  inlet  for  acid.  From  the 
reservoir  I,  concentrated  sulphuric  acid  is  allowed  to  run  in 
through  a  lead  pipe  conduit.  For  100  parts  of  calcium  acetate 
GO  parts  of  sulphuric  acid  are,  as  a  rule,  allowed.  Decompo- 
sition at  first  progresses  by  itself  and  about  J  of  the  acetic  acid 
•present  distils  over.  Slight  heating  then  becomes  necessary. 
'The  stirrers  must  be  kept  constantly  in  operation.  The  acetic 
acid  vapors  pass  from  a  into  a  clay  condenser  c?,  and  run 
through  c  into  a  storage-reservoir  d  of  clay  ;  all  other  mater- 
ials would  in  a  short  time  be  destroyed. 

The  crude  acid  still  contains  impurities,  such  as  sulphurous 
acid,  traces  of  sulphuretted  hydrogen,  etc.,  which  by  its  par- 
tial decomposition  the  sulphuric  acid  has  yielded  together  with 
the  tar  of  the  crude  acid  ;  besides  it  contains  resinous  and  tarry 
substances  and  coloring  matter  which  are  removed  by  rectifi- 
•cation  over  potassium  chromate. 

For  this  purpose  acid  is  allowed  to  run  from  the  reservoir  d 
•into  the  still,  and  after  the  addition  of  water  is  rectified.  The 
-apparatuses  used  at  the  present  time  at  once  furnish  a  product 
of  09  per  cent,  and  more.  In  the  illustration,  e  is  the  column, 
/a  pipe  condenser  with  return  pipe,  and  g  a  condenser  for  the 
acid-.  For  the  preparation  of  vinegar  for  comestible  purposes 
the  acid  is  again  rectified  in  the  still  h,  with  the  addition  of  po- 
tassium chromate,  a  perfectly  clear  product  without  detrimen- 
tal odor  being  obtained  from  the  clay  condenser  i.  The  still 
h  may  be  of  enameled  cast  iron  and  is  provided  with  a  heating 
jacket.  The  movement  of  the  fluid  is  effected  by  means  of 
-compressed  air  and  the  munte-jus  m,  d,  and  L 


TREATMENT    OF    THE    WOOD    VINEGAR.  309^ 

FIG.  83. 


1.  Engine-house  ;  2.  Fire  passage;  3.  Boiler-house;  4.  Lime  Kiln  ;  5.  Storage- 
for  calcium  acetate ;  6.  Lime  kiln. 

The  preparation  of  glacial  acetic  acid  is  effected  by  decom- 
posing the  sodium  salt  by  means  of  sulphuric  acid.  By  the 
introduction  of  sodium  sulphate  (Glauber's  salt)  into  the  calr- 


310  MANUFACTURE  OF  VINEGAE. 

cium  acetate  solution,  the  latter  is  converted  into  sodium  ace- 
tate solution,  saturation  being  attained  when  a  clear  filtered 
sample  no  longer  yields  a  precipitate  of  calcium  sulphate  on 
the  further  addition  of  sodium  sulphate. 

The  solution  is  drawn  off  from  the  sediment  and  the  latter 
lixiviated  until  exhausted.  Concentration  to  a  specific  gravity 
of  1.3  is  effected  in  directly  heated  boilers.  The  excess  of  so- 
dium sulphate  crystallizing  out  is  brought  into  perforated  bas- 
kets from  which  the  mother-lye  again  runs  into  the  boilers. 
It  is  then  allowed  to  settle  and  clarify  for  8  to  10  hours  when 
it  is  drawn  of.  The  sediment  consists  of  admixtures  of  the 
raw  materials  which  have  become  insoluble,  t.ar  and  other  con- 
stituents. In  coolers  or  crystallizing  vessels  the  greater  portion 
of  the  sodium  acetate  is  deposited  in  three  to  five  days,  and 
the  crude  salt  is  frequently  directly  sold.  The  mother-lye  is 
drawn  off,  is  again  concentrated,  crystallized,  and  so  on  until 
exhausted.  The  residue  is  then  evaporated  and  heated  to  a 
red  heat  in  order  to  obtain  sodium  carbonate,  or  heated  to 
melting  to  remove  the  tar,  the  sodium  acetate  thus  obtained 
being  separated  from  the  coal  by  dissolving  in  water.  The 
tarry  admixtures,  tar  oils  of  various  kinds,  adhere  with  great 
tenacity  to  all  the  products  of  distillation,  even  the  crystals 
first  obtained  being  not  perfectly  pure.  They  are  purified  by 
again  dissolving  them,  concentrating  the  solution  and  crystal- 
lizing. The  crystals  are  then  melted  in  an  iron  boiler  in  the 
water  of  crystallization  and,  after  evaporating  the  latter,  heated 
until  melted  the  second  time.  The  salt  is  now  anhydrous  and 
great  care  is  required  to  prevent  it  from  burning.  It  is  then  de- 
composed by  concentrated  sulphuric  acid  in  glass  retorts  in  a 
sand  bath.  For  92  parts  salt  98  parts  sulphuric  acid  are  used. 
From  the  distillate  the  glacial  acetic  acid  separates,  on  cooling, 
in  the  form  of  crystals. 

At  the  present  time  the  vacuum  process  is  generally  employed, 
it  yielding  at  once  a  highly  concentrated  acetic  acid.  The 
apparatus  used  for  this  purpose  as  constructed  by  the  firm  of 
J.  H.  Meyer,  at  Hanover-Hainholz,  Germany,  consists  of  cast 


TREATMENT    OF    THE    WOOD    VINEGAR.  311 

iron  boilers  which  according  to  the  size  of  the  plant,  have 
a  capacity  of  from  240  to  3300  Ibs.  of  calcium  acetate.  Each 
boiler  is  equipped  with  a  stirrer.  The  charge  is  introduced 
through  a  manhole  in  the  cover  and  the  boiler  is  emptied,  as 
a  rule,  through  an  aperture  in  the  bottom  through  which  the 
gypsum  can  be  pushed  out  by  the  stirrer. 

When  the  gray  acetate  is  uniformly  distributed  in  the  boiler, 
the  calculated  quantity  of  sulphuric  acid  is  allowed  to  run  in. 
Decomposition  then  commences,  so  much  heat  being  thereby 
liberated  that  a  large  portion  of  the  acetic  acid  distils  over 
without  the  use  of  a  vacuum.  When  distillation  slackens, 
vacuum  is  applied  and  distillation  carried  on  to  the  end,  the 
bottom  of  the  boiler  being  at  the  same  time  heated  by  steam. 
From  220  Ibs.  of  acetate  and  132  Ibs.  of  sulphuric  acid,  165 
Ibs.  of  crude  acetic  acid  with  80  per  cent,  acid  are  under 
normal  conditions  obtained.  The  crude  acid  contains  small 
quantities — 0.005  to  0.05  per  cent. — of  sulphurous  acid. 

For  the  preparation  of  acid  intended  for  technical  purposes 
only,  the  crude  acetic  acid  is  further  purified  by  subjecting  it 
once  more  to  distillation  in  more  simple  copper  stills  generally 
provided  with  a  worm  silvered  inside.  For  the  preparation 
of  high-graded,  entirely  pure  acid  and  of  vinegar  essence  suit- 
able for  comestible  purposes,  the  crude  acetic  acid  is  decom- 
posed in  a  column  apparatus. 

In  order  to  finally  prepare  chemically  pure  vinegar  (99  to 
100  per  cent.)  from  that  fraction  which  contains  96  to  98.5 
per  cent,  of  acetic  acid,  the  distillate  is  further  treated  with 
potassium  permanganate  for  the  oxidation  of  contaminating 
admixtures  still  present,  and  then  distilled  from  the  "  fine  acid 
apparatus  ".  This  apparatus  has  a  still  of  copper,  but  a  head 
and  worm  of  silver  to  prevent  contamination  by  copper  acetate. 
Generally  the  first  and  last  runnings  only  are  removed,  the 
middle  running  being  perfectly  pure  acetic  acid. 

Glacial  acetic  acid,  of  the  highest  concentration,  acidum 
aceticum  glaciale,  can  also  be  prepared  as  follows  :  Freshly  de- 
hydrated sodium  acetate  is  distilled  with  concentrated  sulphuric 


312  MANUFACTURE  OF  VINEGAR. 

acid,  or  water  is  withdrawn  from  high-graded  acetic  acid  by 
rectifying  it  over  fused  calcium  chloride. 

In  the  first  case  9J  parts  by  weight  of  sulphuric  acid  are 
slowly  poured  upon  100  parts  by  weight  of  sodium  acetate  free 
from  water  to  prevent  the  escape,  without  being  condensed, 
of  a  portion  of  the  acetic  acid  vapors' evolving  with  great  vigor. 
Heat  is  applied  only  after  the  introduction  of  the  total  quan- 
tity of  sulphuric  acid,  and  the  first  four-fifths  of  the  distillate 
are  caught  by  themselves,  because  the  last  portion  of  it  has  an 
empyreumatic  odor,  while  the  first  portions  contain  only  sul- 
phurous acid  which  is  removed  by  rectifying  the  acid  over 
potassium  dichromate. 

According  to  the  second  process  glacial  acetic  acid  may 
even  be  prepared  from  50  per  cent,  acetic  acid  by  distilling 
the  latter  with  fused  (anhydrous)  calcium  chloride.  The  gla- 
cial acetic  acid  thus  obtained  contains  considerable  quantities 
of  hydrochloric  acid.  It  is  freed  from  it  by  rectification  over 
anhydrous  sodium  acetate,  a  still  with  a  silver  head  and  worm 
being  used,  and  the  precaution  taken  not  to  cool  the  worm  too 
much  as  otherwise  the  acetic  acid  might  crystallize  in  it. 

The  calcium  chloride  containing  water  which  remains  be- 
hind is  dehydrated  by  heating  in  shallow  vessels  and  then 
heated  to  red  hot  fusion,  this  being  necessary  for  the  destruc- 
tion of  all  organic  substances  present.  The  preparation  of  gla- 
cial acetic  acid  should,  if  feasible,  be  undertaken  in  the  cool 
season  of  the  year.  The  distillate  running  from  the  condenser 
is  collected  in  stone-ware  pots  which  are  covered  and  exposed 
to  a  low  temperature,  the  greater  portion  of  the  fluid  congeal- 
ing thereby  to  a  crystalline  mass.  The  position  of  the  pots  is 
then  changed  so  that  the  portion  which  has  remained  fluid  can 
run  off ;  this  is  added  to  the  next  rectification  over  calcium 
chloride.  By  placing  the  pots  in  a  heated  room  the  anhydrous 
acetic  acid  is  melted  and  then  filled  in  bottles.  Glacial  acetic 
acid  thus  prepared  will  stand  the  test  usually  applied  in  com- 
merce. It  consists  in  bringing  the  acetic  acid  together  with 
lemon  oil.  Anhydrous  acetic  anhydride  dissolves  lemon  oil 


ACETATES    AND    THEIR    PREPARATION.  313- 

in  every  proportion,  but  in  the  presence  of  even  a  very  small 
quantity  of  water  solubility  decreases  in  a  high  degree. 
Another  commercial  test  consists  in  compounding  the  acetic 
acid  as  well  as  the  glacial  acetic  acid  and  the  diluted  acid,, 
with  solution  of  potassium  permanganate  till  it  appears  rasp- 
berry red  ;  pure  acid  remains  permanently  red,  while  if  em- 
pyreumatic  substances  are  present,  t-he  red  color  disappears- 
rapidly. 

However,  an  acid  free  from  empyreumatic  substances,  but 
containing  sulphurous  acid,  may  also  exert  a  discoloring  effect 
upon  the  potassium  permanganate  solution.  It  is,  therefore, 
advisable  before  making  the  test  for  empyreumatic  substances- 
to  test  the  acid  for  sulphurous  acid.  This  is  done  by  com- 
pounding the  acid  with  potassium  permanganate,  allowing  it 
to  stand  until  discolored  and  then  adding  barium  chloride 
solution  ;  sulphurous  acid,  if  present,  has  now  been  changed 
to  sulphuric  acid,  the  fluid  is  rendered  turbid  by  barium  chlo- 
ride, and  after  standing  for  some  time  a  white  precipitate  is- 
separated.  Such  acid  should  again  be  rectified. 


CHAPTER   XXV. 

ACETATES  AND  THEIR  PREPARATION. 

The  acetates,  particularly  those  of  calcium,  potassium,  so- 
dium, barium,  lead,  copper,  aluminium  and  iron  are  exten- 
sively used  in  the  industries  and  are  produced  in  large  quan- 
tities. Calcium  acetate  and  sodium  acetate  are  as  previously 
explained  initial  products  for  the  preparation  of  acetic  acid  and 
acetone,  for  which  barium  acetate  may  also  be  used. 

All  the  acetates  are  more  or  less  readily  soluble  in  water. 
By  the  addition  of  sulphuric  acid  the  acetic  acid  is  liberated 
without  perceptible  evolution  of  gas.  The  solutions  of  the 
acetates  are  precipitated  by  nitrate  of  silver  ;  the  precipitate 


,314  MANUFACTURE    OF    VINEGAR. 

of  acetate  of  silver  is  crystalline  and  soluble  in  100  parts  of 
water. 

When  mixed  with  equal  parts  of  alcohol  and  double  the 
weight  of  sulphuric  acid,  acetic  ether  is  evolved,  which  is 
recognized  by  its  characteristic  fruit-like  odor. 

Ferric  chloride  imparts  to  the  very  dilute  aqueous  solution 
an  intense  bright-red  color. 

From  other  similar  combinations  the  acetates  are  distin- 
guished by  yielding  acetone  when  subjected  to  destructive 
distillation,  and  marsh-gas  when  distilled  with  caustic  potash. 
When  heated  with  arsenic  the  very  peculiar  and  disagreeable 
odor  of  cacodyl  is  evolved. 

Potassium  acetate,  KC2H3Or  Dry  potassium  acetate  forms  a 
snow-white,  somewhat  lustrous,  not  very  heavy,  laminate  or 
foliated  crystalline,  pulverulent  mass.  It  has  a  warming, 
slightly  pungent  salty  taste,  and  its  odor  is  not  acid.  It  turns 
red  litmus  paper  slightly  blue,  but  does  not  redden  phenol- 
phthalein.  It  rapidly  absorbs  moisture  from  the  air  and  deli- 
quesces. At  the  ordinary  temperature  it  is  soluble  in  about 
J  part  of  water  or  1 J  parts  of  alcohol.  Boiling  water  dissolves 
eight  times  the  quantity  of  its  weight  of  potassium  acetate, 
such  a  solution  boiling  at  329°  F.  The  dry  salt  when  tritur- 
ated with  iodine  yields  a  blue  mixture,  the  latter  giving  with 
water  a  brown  solution. 

When  heated,  potassium  acetate  melts,  without  suffering 
decomposition,  at  557.3°  F.,  and  on  cooling  congeals  to  a 
radiated  crystalline  mass.  On  heating  to  780°  F.  acetic  acid 
escapes  and,  after  incineration,  potassium  carbonate  colored 
gray  by  coal  remains  behind. 

By  adding  ferric  chloride  solution  to  potassium  acetate 
solution,  a  liquid  of  a  blood-red  color  is  obtained  which  besides 
potassium  chloride  contains  ferric  acetate.  By  heating  the 
solution  to  boiling  a  red  precipitate  of  basic  ferric  acetate  is 
separated,  the  supernatant  liquid  becoming  colorless,  provided 
sufficient  potassium  acetate  was  present  and  the  ferric  chloride 
solution  did  not  contain  too  much  hydrochloric  acid. 


ACETATES    AND    THEIR    PREPARATION.  315 

Potassium  acetate  is  prepared  by  bringing  into  a  vat  or  boiler 
purified  wood  vinegar  and  adding  potash  in  small  quantities. 
The  liquid  foams,  and  the  tarry  substances  that  separate  on 
the  surface  are  removed  by  means  of  a  perforated  ladle.  The 
addition  of  potash  is  continued  till  the  solution  is  neutralized 
when  it  is  allowed  to  settle.  The  clarified  solution  is  then 
evaporated  todryness  in  an  iron  pan,  the  tarry  substances  ap- 
pearing during  this  operation  being  removed.  When  the 
product  is  dry,  the  fire  is  increased  and  the  salt  melted  in  the 
water  of  crystallization.  When  the  mass  has  acquired  a  but- 
yraceous  appearance,  the  fire  is  withdrawn  and  the  salt  allowed 
to  cool,  otherwise  it  would  change  to  potassium  carbonate. 
When  cold  the  melt  is  again  dissolved  in  water,  filtered  and 
further  worked. 

Another  method  of  producing  potassium  acetate  is  by  decom- 
posing normal  acetate  of  lead  (sugar  of  lead)  with  pure 
carbonate  or  sulphate  of  potassium.  To  detect  the  presence 
of  lead  it  should  be  tested  with  sulphuretted  hydrogen,  which 
in  the  presence  of  this  metal  produces  a  slightly  brown  pre- 
cipitate. To  obtain  a  pure  product  the  decanted  liquid  is 
treated  with  sulphuretted  hydrogen,  and,  after  separating 
from  the  precipitate  and  adding  a  small  quantity  of  acetic  acid, 
is  evaporated  in  a  stone-ware  vessel. 

Chemically  pure  potassium  acetate  is  prepared  by  bringing 
400  parts  of  30  per  cent,  acetic  acid  into  an  acid-proof  enameled 
boiler  and  gradually  introducing  138  parts  of  pure  potassium 
carbonate  or  200  parts  of  potassium  bicarbonate  until  the 
solution  is  finally  neutral  or  shows  but  a  slight  alkaline  reac- 
tion. Solution  has  finally  to  be  assisted  by  heating. 

The  solution  is  then  acetified  with  acetic  acid  and  evaporated 
to  a  small  volume  on  a  steam-bath  or  better  over  an  open  fire. 
Some  acetic  acid  is  next  added  and  the  mass  is  then  evaporated 
till  it  is  dust-dr}',  being  constantly  stirred  with  a  porcelain 
spatula  during  this  operation.  The  resulting  dust-dry,  crumbly 
powder  is  brought  into  dry  hot  vessels,  which  are  immediately 
closed  with  corks  and  the  latter  are  coated  with  paraffine. 


316  MANUFACTURE  OF  VINEGAR. 

Too  strong  heating  should  be  avoided,  otherwise  decomposition- 
takes  place,  acetone  being  formed. 

Pure  potassium  acetate  should  dissolve  in  two  parts  of  water 
and  the  solution  must  not  redden  phenol  phthalein,  otherwise 
it  contains  more  than  traces  of  potassium  carbonate.  A  5  per 
cent,  aqueous  solution  should  not  be  rendered  turbid  or  colored 
(presence  of  metals)  by  hydrogen  sulphide,  and  not  altered  by 
barium  nitrate  after  the  addition  of  dilute  nitric  acid,  other- 
wise it  is  contaminated  with  sulphate. 

Potassium  acid  acetate  or  potassium  diacetate,  KC2H302C2H402, 
is  formed  by  evaporating  a  solution  of  the  neutral  salt  in  excess 
of  acetic  acid  ;  it  crystallizes  by  slow  evaporation  in  long,  flat- 
tened prisms.  It  is  very  deliquescent  and  decomposes  at  392° 
F.,  giving  off  crystallizable  acetic  acid. 

Sodium  acetate,  NaC2H302. — The  manner  of  preparing  this 
salt  in  the  manufacture  of  wood  vinegar  has  already  been  de- 
scribed. It  can  be  obtained  in  a  manner  similar  to  that  of  the 
potassium  salt  by  dissolving  carbonate  of  soda  in  acetic  acid, 
evaporating  the  solution,  and  setting  the  liquid  aside  to  crys- 
tallize. The  crystals  form  large,  colorless,  oblique  rhombic 
prisms.  Their  composition  is  NaC2H302  -f  3H20  ;  they  are 
soluble  in  3  parts  of  cold,  in  a  less  quantity  of  boiling,  water, 
and  in  5  of  alcohol. 

The  taste  of  sodium  acetate  is  cooling  and  saline.  When 
exposed  to  dry  air  it  loses  its  three  equivalents  of  water,  but 
regains  them  in  a  moist  atmosphere.  After  being  melted  it  is 
deliquescent  and  takes  up  7  equivalents  of  water.  It  becomes 
a  liquid,  supersaturated  solution  which  crystallizes,  with  evolu- 
tion of  heat,  immediately  after  a  fragment  of  dry  or  crystallized 
sodium  acetate  is  thrown  into  it. 

Sodium  acetate  is  used  for  the  preparation  of  acetic  acid, 
acetic  ether,  and  in  medicine.  It  has  also  been  recommended 
for  the  preservation  of  animal  and  vegetable  tissues,  it  being 
used  in  the  form  of  a  powder  in  place  of  common  salt. 

Ammonium  acetate,  neutral  acetate  of  ammonia,  NH4C8H302. 
-This  substance  is  obtained  by  neutralizing  acetic  acid  with 


ACETATES    AND    THEIR    PREPARATION.  317 

carbonate  of  ammonia,  or  better,  by  saturating  glacial  acetic 
acid  with  dry  ammonia  gas.  It  is  very  difficult  to  obtain  in 
the  crystalline  form  on  account  of  its  aqueous  solution  giving 
off  ammonia  when  evaporated,  thus  becoming  converted  into 
the  acid  salt.  When  subjected  to  dry  distillation  ammonia  gas 
escapes  first;  above  330°  F.  there  is  formed,  besides  water, 
chiefly  acetamide  (C2H5NO),  a  white  crystalline  body  which  is 
also  formed,  besides  alcohol,  on  heating  acetic  ether  with  liquid 
ammonia  in  a  closed  vessel  to  about  266°  F. 

In  medicine  ammonium  acetate  has  long  been  used  as  a 
diaphoretic. 

Calcium  acetate,  Ca  (C2H302)2.  The  preparation  of  calcium 
acetate  has  already  been  described  under  wood  vinegar. 

The  crystals  of  the  pure  salt  form  white  acicular  prisms 
which  effloresce  in  the  air  and  are  soluble  in  water  and  in  al- 
cohol ;  they  have  a  bitter,  salty  taste.  They  are  decomposed 
by  heat  into  acetone  and  calcium  carbonate.  A  mixture  of 
this  salt  and  of  potassium  oxalate  gives,  on  heating,  propylene 
(C3H6),  while  a  mixture  of  carbonates  remains  behind.  By 
destructive  distillation  of  equal  equivalents  of  acetate  and  ben- 
zoate  of  calcium,  acetophenone  (C8H80)  is  obtained,  which  by 
treatment  with  nitric  acid  is  converted  into  nitro-acetophenone 
(C8H7N03).  By  heating  the  latter  with  zinc-dust  and  soda- 
lime,  Emmerling  and  Engler  claim  to  have  obtained  artificial 
indigo-blue.  But  the  quantity  of  the  latter  thus  obtained  is 
always  very  small,  and  it  appears  to  be  very  difficult  to  ascer- 
tain the  precise  condition  under  which  the  transformation 
takes  place. 

Barium  acetate,  (C2H302)2Ba+l  J  H20,  finds  at  present  exten- 
sive application  in  the  industries,  especially  in  the  preparation 
of  acetone,  as  it  is  decomposed  at  a  lower  temperature  than 
calcium  acetate,  and  leaves  a  residue — barium  carbonate — 
which  can  again  be  used  for  the  preparation  of  the  acetate, 
while  the  residue  from  calcium  carbonate  is  of  no  value. 

Barium  acetate  is  prepared  from  the  mineral  witheritefin  a 
manner  similar  to  calcium  acetate,  the  only  difference  being  as 


318  MANUFACTURE    OF    VINEGAR. 

to  whether  the  witherite  is  used  in  lumps  or  in  the  form  of  pow- 
der. In  the  first  case  the  wood  vinegar  is  allowed  to  act  for 
some  time  upon  the  witherite  by  allowing  it  to  run  over  the 
mineral,  or  after  filling  several  vessels  (a  battery)  with  the 
witherite,  dissolving  it  by  conducting  gaseous  acetic  acid 
through  the  vessels.  Provisions  must  of  course  be  made  for 
carrying  off  the  carbonic  acid  that  is  evolved. 

The  use  of  witherite  in  the  form  of  powder  instead  of  in 
lumps,  is  more  advantageous ;  but  as  the  powder,  in  conse- 
quence of  its  own  specific  gravity  has  a  tendency  to  settle  on  the 
bottom,  a  powerful  mixing  and  stirring  apparatus  has  to  be 
provided.  When  used  in  the  form  of  a  fine  powder  the  with- 
erite must  be  sifted  upon  the  surface  of  the  fluid  containing 
the  acetic  acid,  as  it  readily  forms  lumps,  which  drop  to  the 
bottom  and  are  dissolved  only  with  difficulty.  As  the  evolu- 
tion of  carbonic  acid  is  by  no  means  tumultuous  the  vessels 
used  can  be  kept  quite  full. 

The  barium  acetate  solution  obtained  by  either  method  may 
be  neutral  but  should  never  show  an  acid  reaction.  It  is 
passed  through  a  filter  press  and  then  evaporated  in  the  usual 
manner,  care  being  taken  not  to  let  it  boil  up ;  for  this  reason 
it  is  advisable  to  effect  evaporation  in  a  vacuum. 

Crystallization  is  effected  in  the  customary  manner.  The 
resulting  crystals  are  freed  from  the  mother-lye  and,  if  not 
colored  too  dark  (by  empyreumatic  substances),  can  be  imme- 
diately used.  Purification  is  effected  by  recrystallization,  dis- 
solving the  crystals  in  water,  by  treatment  with  animal  char- 
coal, china  clay  or  bole,  but  best  by  a  small  addition  of  sulphuric 
acid,  whereby  barium  sulphate  is  formed  which  falls  to  the 
bottom,  carrying  with  it  the  empyreumatic  substances.  After 
settling  the  clear  liquor  is  drawn  off  or  the  mixture  is  passed 
through  a  filter-press.  The  clear  solution  is  evaporated  in 
the  customary  manner  and,  after  crystallization,  the  mother- 
lye  is  separated  and  the  crystals,  if  necessary,  are  once  more 
purified.  The  mother-lyes  are  utilized  by  adding  them  to  the 
solutions  first  obtained.  If  they  contain  too  many  foreign 


ACETATES    AND    THEIR    PREPARATION.  319' 

substances,  they  are  evaporated  to  dry  ness,  dried,  ignited  and 
used  for  solution  in  acetic  acid. 

According  to  another  method  barium  acetate  is  prepared 
by  allowing  equivalent  quantities  of  barium  chloride  and  so- 
dium acetate  to  act  upon  each  other.  For  this  purpose  the  ade- 
quate quantity  of  barium  chloride  is  dissolved  in  water  so  that, 
if  feasible,  an  oversaturated  solution  is  obtained,  and  to  this 
solution,  whilst  boiling  vigorously,  sodium  acetate  in  fine- 
crystals  is  gradually  added.  During  this  reaction  the  contents 
of  the  boiler  must  constantly  be  kept  boiling  vigorously. 
Decomposition  progresses  quite  rapidly.  The  sodium  chloride 
which  is  separated  is  removed  and  the  progress  of  reaction 
watched  by  taking  samples.  When  decomposition  is  complete, 
the  contents  of  the  boiler  are  allowed  to  settle,  and  the  solution 
drawn  off  from  the  sediment  is  crystallized.  The  crystals  are 
then  separated  from  the  mother-lye  and  the  last  remnants  of 
the  latter  removed  either  by  suction  or  by  means  of  a  centri- 
fugal, the  crystals  being  at  the  same  time  washed  with  water 
and,  if  required,  recry stall i zed  from  pure  water.  The  mother- 
lye  always  contains  common  salt  and  is  again  utilized  for 
dissolving  the  barium  chloride. 

The  crystallized  barium  acetate  obtained  at  the  ordinary  tem- 
perature contains  1  molecule  of  water,  while  that  crystallized 
at  32°  F.  possesses  3  molecules  of  water  and  is  amorphous  with 
lead  acetate.  On  exposure  to  the  air  the  crystals  effloresce 
and  the  solutions  show  an  alkaline  reaction.  The  salt  is  sol- 
uble in  1.5  parts  of  cold,  and  1.1  parts  of  boiling  water,  and 
in  67  parts  of  boiling,  and  in  100  parts  of  cold,  alcohol. 

Strontium  acetate. — This  salt  is  prepared  in  a  manner  similar 
to  that  of  the  preceding.  The  crystals  obtained  at  32°  F.  con- 
tain 5  equivalents  of  water  and  those  at  59°  F.  1  equivalent. 

With  strontium  nitrate  it  gives  a  double  salt  forming  beau- 
tiful crystals  which  contain  3  equivalents  of  water.  On  heat- 
ing they  first  yield  their  water  of  crystallization  and  then 
detonate,  a  beautiful  purple  flame  being  formed. 

Magnesium   acetate  is  prepared   by  dissolving  magnesia  alba 


.320  MANUFACTURE    OF    VINEGAR. 

or  usta  in  acetic  acid.  It  crystallizes  with  difficulty  and  is 
readily  soluble  in  water  and  spirits  of  wine.  Only  a  very  small 
portion  of  the  solution  is  decomposed  by  ammonia.  By  de- 
structive distillation  it  yields  acetic  acid,  while  magnesia 
remains  behind. 

Aluminium  acetate. — Large  quantities  of  aluminium  acetate 
-are  used  under  the  name  of  red  mordant  in  dyeing,  as  well  as 
for  water-proofing  tissues. 

Three  combinations  of  aluminium  with  acetic  acid  are 
•known,  namely,  normal  f  aluminium  acetate,  and  two  basic 
acetates  which  according  to  their  content  of  acetic  acid  it  is 
•customary  to  distinguish  as  f  and  £  aluminium  acetates. 

The  normal  or  f  aluminium  acetate,  A]2(CH3C02)6  is  obtained 
by  decomposing  aluminium  sulphate  with  barium  acetate,  or 
by  dissolving  aluminium  hydrate  in  the  calculated  quantity 
of  acetic  acid.  It  is  only  known  in  a  liquid  form.  When 
•evaporated  even  at  below  100°  F.  it  is  decomposed  to  basic- 
acetates  of  different  compositions.  In  boiling  the  solution  in- 
soluble basic  aluminium  acetate  is  separated,  the  composition 
of  which  is  not  yet  accurately  known. 

The  basic  aluminium  f  acetate,  A12(OH2)(CH3C02)4  is  obtained 
by  dissolving  aluminium  hydrate  in  the  calculated  quantity 
•of  acetic  acid.  By  evaporating  the  solution  at  below  100°  F., 
it  is  reduced  to  a  hornlike  mass  which  gives  a  clear  solution 
with  water,  especially  if  the  latter  has  been  acidulated*  with 
acetic  acid.  By  heating  above  100°  F.  insoluble  basic  alum- 
inium acetate  is  separated. 

The  bade  aluminium  J  acetate,  A12(OH4)(CH3C02)2  separates 
on  heating  or  evaporating  the  solutions  of  the  abovementioned 
combinations. 

For  the  preparation  of  aluminium  acetate  in  larger  quantities, 
aluminium  hydrate  is  seldom  used  as  the  initial  material, 
-aluminium  sulphate  or  ordinary  alum  being  generally  decom- 
posed by  means  of  a  carbonate,  lead  acetate  or  calcium  acetate. 
The  aluminium  hydrate  thus  obtained  is  then  dissolved  in 
-acetic  acid. 


ACETATES    AND    THEIR    PREPARATION.  321 

Aluminium  sulphate  is  as  a  rule  preferred  to  alum,  it  being 
cheaper  and  can  also  be  obtained  free  from  iron,  which  is  of 
great  importance  as  regards  the  use  of  aluminium  acetate  in 
Turkey  red  dyeing  (for  alazaririe  colors)  as  iron  imparts  a 
brown  tinge  to  the  red. 

Aluminium  acetate  is  generally  prepared  by  dissolving  30 
parts  by  weight  of  aluminium  sulphate  in  80  parts  of  cold 
water,  then  adding  36  parts  by  weight  of  30  per  cent,  acetic 
acid  (of  1.041  specific  gravity),  and  introducing  into  this  mix- 
ture, whilst  stirring  constantly,  13  parts  by  weight  of  whiting 
triturated  with  20  parts  by  weight  of  water. 

Decomposition  does  not  proceed  as  smoothly  as  would  ap- 
pear from  the  chemical  equation  ;  it  must  be  effected  so  that 
heating  of  any  kind  is  excluded. 

By  reason  of  the  evolution  of  carbonic  acid  the  decomposi- 
tion-vessel must  be  of  such  a  size  that  it  is  filled  only  two- 
thirds  full.  It  should  be  furnished  with  a  stirrer  to  keep  the 
heavy  whiting  suspended,  and  thus  cause  uniformity  of  de- 
composition. 

The  whiting  should  be  intimately  stirred  together  with  'the 
water  and  in  order  to  retain  admixed  impurities  such  as  sand, 
straw,  etc.,  poured  in  small  quantities  through  a  fine-mesh 
sieve.  When  all  the  whiting  has  been  introduced  the  stirrer  is 
kept  running  for  5  or  6  hours  longer,  and  the  mass  is  then  al- 
lowed to  stand  quietly.  Since  decomposition  is  not  completely 
finished  in  24  hours,  it  is  accelerated  after  that  time  by  again 
running  the  stirrer  for  six  hours,  when  the  mixture  is  brought 
into  a  filter-press  and  the  heavy  solution  collected  by  itself. 
The  press-cakes  are  thoroughly  washed  and  the  wash- water  is 
used  for  dissolving  fresh  portions  of  aluminium  sulphate. 
The  cakes  remaining  in  the  frame  of  the  filter-press  may,  if 
pure  white,  be  dried  and  sold  as  gypsum ;  otherwise  they  can 
be  utilized  as  fertilizer. 

In  place  of  whiting  some  manufacturers  use  sodium  bicar- 
bonate ;  667  parts  by  weight  of  aluminium  sulphate  are  dis- 
solved in  15000  parts  by  weight  of  warm  water.  Into  this 
21 


322  MANUFACTURE  OF  VINEGAR. 

solution  are  introduced  very  slowly  and  whilst  constantly 
stirring,  504  parts  by  weight  of  sodium  bicarbonate,  the  bicar- 
bonate product  of  the  manufacture  of  ammonia-soda  being 
suitable  for  the  purpose.  Alumina  in  a  gelatinous  form  is 
precipitated.  It  is  allowed  to  settle,  washed  free  from  salt 
and  pressed  to  a  weight  of  1750  parts.  200  parts  by  weight  of 
the  gelatinous  aluminium  hydrate  are  dissolved  in  150  parts 
by  weight  of  50  per  cent,  acetic  acid.  One  liter  of  the  mordant 
thus  obtained  contains  35.3  grammes  of  alumina.  In  place 
of,  sodium  bicarbonate,  ammonia-soda  may  be  used  in  the 
proportion  of  1  part  by  weight  of  aluminium  sulphate  to  3.6 
parts  by  weight  of  soda. 

Many  manufacturers  prefer  to  effect  the  decomposition  of 
the  aluminium  sulphate  with  lead  acetate  instead  of  with 
whiting  or  sodium  carbonate.  Since  lead  sulphate  is  insoluble 
the  decomposition  of  the  aluminium  sulphate  solution  is  more 
perfect.  In  practice  it  is  found  advantageous  to  employ  equal 
parts  of  aluminium  sulphate  and  acetate  of  lead,  or  even  a 
rather  less  quantity  of  the  latter.  The  aluminium  sulphate 
is  dissolved  in  boiling  water,  and  the  powdered  lead  acetate 
added  to  the  solution.  About  one-tenth  of  crystallized  carbon- 
ate of  soda,  or  a  little  carbonate  of  lime,  is  added  to  the  alum 
to  combine  with  the  free  acid.  The  three  following  receipts 
serve  to  indicate  the  proportions  employed  :— 

I.  Dissolve  100  pounds  of  aluminium  sulphate  in  50  gallons 
of  boiling  water,  and  add  10  pounds  of  acetate  of  lead  in  fine 
powder,  stirring  the  mixture  well  at  first,  and  likewise  several 
times  during  cooling. 

II.  Dissolve  100  pounds  of  aluminium  sulphate  in  50  gallons 
of  boiling  water,  add  slowly  10  pounds  of  crystallized  carbonate 
of  soda,  and  then  stir  in  50  pounds  of  acetate  of   lead  in 
powder. 

III.  Dissolve  100    pounds  of   aluminium   sulphate  in    50 
gallons  of  boiling  water,  and  add  in  small  portions  6  pounds 
of  crystallized  carbonate  of  soda,  and  then  stir  in  50  pounds 
of  acetate  of  lead,  in  powder,  as  before. 


ACETATES    AND    THEIR    PREPARATION.  323 

The  cheapest  method  of  preparing  aluminium  acetate  is 
from  calcium  acetate  and  aluminium  sulphate,  the  principal 
condition  being  not  to  use  a  too  tarry  gray  acetate  as  other- 
wise the  final  product  turns  out  too  dark  and  can  be  decolor- 
ized only  with  difficulty.  Calcium  acetate  contains,  as  a  rule, 
a  larger  quantity  of  calcium  carbonate,  and  this  quantity  has 
previously  to  be  accurately  determined  in  order  to  calculate 
the  quantity  of  aluminium  sulphate  required.  In  practice 
this  calculation  is  avoided  by  having  always  on  hand  clear 
solutions  of  both  salts  and,  when  an  excess  of  one  or  the  other 
salt  is  found  in  the  aluminium  acetate  solution,  correcting  it 
by  the  addition  of  one  or  the  other  solution,  so  that  a  pure 
aluminium  acetate  solution  results. 

As  a  rule  100  parts  by  weight  of  calcium  acetate  and  70 
parts  by  weight  of  aluminium  sulphate  are  dissolved,  each  by 
itself,  in  sufficient  water  to  obtain  solutions  of  5  to  6°  Be. 
The  solutions  are  filtered  and  after  bringing  the  separate  solu- 
tions into  the  vessels  located  over  the  precipitation  vat,  pre- 
cipitation is  effected.  On  account  of  the  evolution  of  carbonic 
acid,  the  vat  should  not  be  kept  too  full. 

When  a  determined  quantity  of  fluid  has  been  consumed 
and  evolution  of  gas  has  ceased,  a  small  quantity  of  the  fluid 
in  the  vat  is  filtered  in  a  small  glass  cylinder,  the  filtrate  di- 
vided into  two  halves,  one  of  which  is  tested  with  barium  chlor- 
ide solution  for  sulphuric  acid,  and  the  other  with  ammonium 
oxalate  or  sulphuric  acid  for  lime.  If  in  one  or  the  other  case 
a  white  precipitate  is  formed  enough  of  one  or  the  other  clear 
solution  previously  mentioned  is  added  until  after  taking  other 
samples  no  precipitate  or  turbidity  is  formed  in  them  ;  the 
aluminium  acetate  solution  then  contains  only  slight  traces  of 
calcium  acetate  or  aluminium  sulphate. 

The  contents  of  the  precipitation-vat  are  passed  through  a 
filter-press  and  the  residue  is  washed.  The  cakes  of  gypsum 
are  not  suitable  for  fertilizing  purposes ;  by  adding  air-slaked 
lime  and  ashes  the)7  may  be  utilized  for  repairing  roads,  etc. 

Manganese    acetate,    Mn(C2H302)2.      This  substance    is    pre- 


324  MANUFACTURE  OP  VINEGAK. 

pared  by  dissolving  freshly  precipitated  mangauous  carbonate 
(MnC03)  in  heated  acetic  acid,  evaporating  the  solution  and 
•crystallizing.  The  crystals  are  rhombic  prisms,  and  occasion- 
ally in  plates  of  an  amethystine  color  ;  they  are  permanent  in 
the  air,  soluble  in  alcohol,  and  in  about  three  times  their 
weight  of  water. 

On  a  large  scale  this  salt  is  manufncturedby  precipitating  a 
-solution  of  manganous  sulphate  *  by  one  of  lime  acetate  and 
.agitating  the  liquor  to  decompose  the  whole  of  the  manganese 
salt. 

It  sometimes  happens  that  a  portion  of  the  manganese  salt 
is  not  acted  upon  by  the  acetate  of  lime,  and  in  this  case  a 
concentrated  solution  of  acetate  of  lead  is  employed  towards 
the  end  of  the  process  to  effect  complete  decomposition.  The 
mixed  precipitate  of  sulphate  of  lime  and  lead  is  filtered  off, 
and  the  filtrate  evaporated  and  crystallized.  The  best  acetate 
of  manganese  is  made  by  adding  to  4  parts  of  manganous  sul- 
phate dissolved  in  3  parts  of  water,  7  parts  of  crystallized 
acetate  of  lead  dissolved  in  3  parts  of  water,  agitating  the  solu- 
tion, and  drawing  off  the  clear  liquor  for  use. 

Acetate  of  manganese  is  used  in  dyeing  and  calico-printing 
to  give  a  brown  color  to  fabrics.  Its  principle  of  action  de- 
pends upon  the  further  oxidation  of  the  manganese. 

Iron  acetate. — Acetic  acid  combines  with  ferrous  oxide 
(FeO)  as  well  as  with  ferric  oxide  (Fe203),  but  only  the 
ferrous  acetate  crystallizes  in  small  greenish-white  needles,  very 
prone  to  Oxidation,  while  ferric  acetate  is  a  dark,  brownish 
red,  uncrystallizable  liquid,  of  powerful  and  astringent  taste. 
Both  salts  dissolve  freely  in  water,  and  are  of  importance  for 
dyeing  and  calico-printing. 

Ferrous  acetate,  Fe(C2H302)2.     Black   mordant.     For  dyeing 

*  Manganons  sulphate  is  prepared  by  mixing  the  dioxide  (pyrolusite)  with  half 
its  weight  of  concentrated  sulphuric  acid  and  heating  in  a  Hessian  crucible  until 
no  more  vapors  escape.  The  residue  is  dissolved  in  water,  filtered,  and  allowed 
to  crystallize  at  an  ordinary  temperature.  The  solution  of  the  salt  when  decom- 
posed with  crystallized  soda  gives  a  precipitate  of  manganous  carbonate. 


ACETATES  AND  THEIR  PREPARATION.          325 

purposes  this  salt  is  prepared  by  dissolving  wronght-iron 
turnings  in  wood-vinegar,  care  being  had  that  some  iron 
remains  undissolved,  as  otherwise  the  salt,  on  exposure  to  the 
air,  is  gradually  partly  converted  into  the  ferric  salt.  This 
oxidation  proceeds,  however,  but  slowly,  the  empyreumatic 
substances  contained  in  the  wood  vinegar  rendering  the  con- 
version rather  difficult.  The  pure  salt  oxidizes  with  great 
rapidity.  For  commercial  purposes  this  compound  is  manu- 
factured as  follows  :  Into  a  large  wooden  vat  or  into  barrels  a 
quantity  of  iron  turnings,  hoops,  or  nails  are  introduced,  and 
hot  crude  wood- vinegar,  freed  by  distillation  from  wood-spirit,, 
is  poured  upon  them.  During  the  solution  of  the  iron  much 
tarry  matter  separates,  which  is  skimmed  off,  and  the  solution, 
is  frequently  agitated  to  free  it  as  much  as  possible  from,  the 
tar.  After  24  hours  the  solution  is  drawn  off.  The  iron* 
being  entirely  coated  with  tar  so  that  it  can  not  be  again  at- 
tacked by  the  wood-vinegar,  it  is  taken  from  the  vat  and  the 
tar  ignited.  The  iron  is  freed  from  the  oxide  formed  by 
sifting  and  can  be  again  used.  The  solution  thus  obtained 
shows  13°  or  14°  Be. 

The  pure  salt  is  obtained  by  dissolving  iron  in  acetic  acid  or 
by  double  decomposition  from  ferrous  sulphate  (14  parts)  and 
lead  acetate  (19  parts) ;  and  cheaper,  but  less  pure,  from 
ferrous  sulphate  and  calcium  acetate. 

If  crude  calcium  acetate  instead  of  wood-vinegar  is  to  be  used 
in  the  preparation  of  this  salt,  a  solution  of  the  calcium  acetate 
of  specific  gravity  1.08  is  mixed  with  half  its  weight  of  ferrous 
sulphate  dissolved  in  2J  times  its  weight  of  water.  On  agitat- 
ing the  mixture,  the  decomposition  is  rendered  complete,  the 
clear  liquor  which  is  siphoned  off  after  the  subsidence  of  the 
sulphate  of  lime  showing  13°  Be.  It  is  kept  in  a  closed  barrel 
in  which  is  hung  a  bag  containing  a  quantity  of  iron  turnings.. 

In  some  factories  the  ferrous  acetate  is  manufactured  by  de- 
composing the  carbonate  of  iron  (FeCOJ  with  lead  acetate;: 
lead  carbonate  precipitates,  and  the  blackish  supernatant  liquor 
is  the  acetate  of  iron  in  a  very  pure  state.  It  is  kept  from  ox- 


320  MANUFACTURE    OF    VINEGAR. 

idizing  by  immersing  in  it  some  bright  iron  filings.     The  lead 
salt  formed  repays  the  cost  of  the  manufacture  of  the  acetate. 

Solution  of  ferrous  acetate  is  used  as  a  mordant  by  dyers,  for 
staining  wood  and  leather  and  in  the  manufacture  of  ink.  The 
commercial  article  generally  shows  a  specific  gravity  of  1.10 
(12°  B.). 

On  account  of  the  avidity  with  which  ferrous  acetate  absorbs 
oxygen,  it  is  of  great  value  as  a  reducing  agent.  It  is,  for  in- 
stance, used  in  the  preparation  of  aniline  from  nitrobenzole 
and  for  similar  reducing  processes. 

Neutral  ferric  acetate,  sesquiacetate  of  iron,  Fe(C2H302)3. — 
For  technical  use  this  combination  is  obtained  by  dissolving 
wrought-iron  in  wood-vinegar  so  that  it  has  a  chance  to  oxi- 
dize in  the  air.  For  this  purpose  wood-vinegar  is  poured  over 
iron  turnings  in  a  vat,  and  after  drawing  off  the  solution  in  a 
few  days,  the  iron  is  for  some  time  left  to  the  action  of  the  ox- 
ygen of  the  air.  It  quickly  oxidizes,  and  by  pouring  back  the 
solution  and  several  times  repeating  the  drawing  off  and  pour- 
ing back,  a  quite  concentrated  solution  of  dark  red  brown, 
nearly  black  color  is  in  a  short  time  obtained.  Heat  must 
not  be  employed  in  the  preparation  of  this  salt,  as  in  such  case 
it  readily  decomposes. 

Neutral  ferric  acetate  may  be  obtained  in  the  pure  state  by 
decomposing  a  solution  of  lead  acetate  by  adding  ferric  sul- 
phate in  slight  excess.  In  the  course  of  24  hours  the  excess 
of  ferric  sulphate  precipitates  as  a  basic  salt.  It  is  also  pro- 
duced, though  more  slowly,  by  dissolving  ferric  hydrate  or 
ferric  carbonate  obtained  by  precipitation,  in  strong  acetic 
acid.  This  method  occupies  more  time,  but  affords  better 
guarantees  for  the  purity  of  the  compound. 

By  dissolving  one  part  of  nitric  acid  or  aqua  regia,  precipi- 
tating the  solution  with  ammonia  and  dissolving  the  washed 
ferric  hydrate  in  10  parts  of  acetic  acid  of  1.042  specific  grav- 
ity, and  evaporating  the  solution  at  between  140°  and  17G°  F. 
an  amorphous  salt  soluble  in  water  and  alcohol  remains,  which 
is,  however,  not  neutral,  as  it  contains  only  two  instead  of  3 


ACETATES    AND    THEIR    PREPARATION.  327 

equivalents  of  acetic  acid  for  1  equivalent  of  ferric  oxide.  By 
dissolving  this  amorphous  salt  in  acetic  acid  and  exposing  the 
dark  red  solution  to  a  low  temperature,  the  neutral  salt  crys- 
tallizes out  in  hydrated,  lustrous,  dark  red  laminse. 

On  heating  the  strongly  diluted  solution  of  this  salt  to 
nearly  the  boiling  point  its  color  becomes  more  intense  and  it 
evolves  a  distinct  odor  of  acetic  acid  without,  however,  produc- 
ing a  precipitate.  The  salt  has  nevertheless  become  more 
basic,  and  an  addition  of  any  soluble  sulphate  or  even  of  free 
sulphuric  acid  immediately  precipitates  the  whole  of  the  iron 
as  insoluble  basic  ferrous  sulphate.  By  heating,  however,  the 
dilute  solution  of  the  pure  acetate  to  boiling,  it  disengages 
acetic  acid  and  separates  a  basic  salt,  which,  if  boiling  be  con- 
tinued, also  loses  its  acid  so  that  ferric  hydrate  remains  behind. 
The  properties  of  this  hydrate  differ,  however,  from  those  of 
ordinary  ferric  hydrate,  it  dissolving  in  concentrated  hydro- 
chloric acid  only  by  long-continued  digestion  or  boiling,  and  is 
scarcely  attacked  by  boiling  concentrated  sulphuric  acid.  In 
acetic  acid  or  dilute  nitric  acid  it  dissolves,  however,  to  a  red 
fluid,  transparent  to  transmitted,  but  opaque  to  reflected,  light. 
By  adding  the  slightest  quantity  of  a  sulphate  or  of  concen- 
trated nitric  or  hydrochloric  acid,  a  granular  precipitate  is 
formed,  which,  however,  redissolves  on  diluting  the  fluid  with 
water.  If  a  solution  of  ferric  acetate  is  heated  in  a  closed  ves- 
sel to  212°  F.  for  a  few  hours,  the  fluid  seen  by  reflected  light 
appears  opaque  and  opalescent.  It  has  also  lost  its  metallic 
taste  and  no  longer  shows  the  other  reactions  of  ferric  salts,  i.e., 
addition  of  ferrocyanide  produces  no  precipitate  nor  does  the 
sulphocyanide  augment  its  red  color.  A  trace  of  sulphuric 
acid  or  any  alkaline  salt  suffices  to  precipitate  the  whole  of  the 
iron  in  solution  as  ferric  hydrate,  of  red  color,  which  is  totally 
insoluble  in  all  acids  at  an  ordinary  temperature ;  dilute  min- 
eral acids  do  not,  however,  produce  a  similar  'precipitate.  It 
is  remarkable  that  this  ferric  hydrate  dissolves  in  water  to  a 
dark  red  fluid  which  can  be  again  precipitated  by  concentrated 
acids  or  alkaline  salts  (Pean  de  St.  Giles). 


MANUFACTURE    OF    VINEGAR. 

From  the  iron  acetates  the  iron  is  precipitated  as  black  fer- 
rous sulphide  by  sulphuretted  hydrogen. 

With  ferric  nitrate,  ferric  acetate  yields  a  crystallizable 
double  salt,  Fe(C2H302)2N03  +  3H20,  the  solution  of  which 
decomposes  on  boiling,  nitric  and  acetic  acids  being  disengaged. 
A  similar  combination  exists  between  the  acetate  and  ferric 
chloride. 

Chromium  acetates. — Acetic  acid  enters  into  combination 
with  chromous  (CrO),  as  well  as  .with  chromic,  oxide  (O203). 
The  salts  are  not  used  in  the  industries  and  are  only  of 
scientific  interest. 

Chromous  acetate,  (C2H302)2Cr  +  H20,  is  prepared  by  mixing 
a  solution  of  chromous  chloride  with  sodium  acetate.  The  salt 
separates  out  in  small,  lustrous  red  crystals  which  are  sparingly 
soluble  in  water  and  alcohol,  and  quickly  oxidize  to  a  greater 
degree  on  exposure  to  the  air,  the  succeeding  salt  being  formed. 

Chromic  acetate. — A  neutral  salt  is  known  and  there  are  very 
likely  several  basic  ones.  The  solution  of  the  neutral  salt, 
which  is  obtained  by  dissolving  chromic  hydrate  in  heated 
acetic  acid,  forms  a  red  fluid,  green  in  a  reflected,  and  red  in 
a  transmitted,  light.  It  is  not  decomposed  by  boiling,  but  by 
ammonia.  The  precipitate,  however,  redissolves,  on  adding 
ammonia  in  excess,  to  a  violet-red  fluid  because  the  hydrate  is 
soluble  in  ammonium  acetate.  Hence,  a  solution  of  the  salt 
acidulated  with  acetic  acid  is  not  precipitated  by  ammonia. 

There  are  also  known  crystallized  combinations  of  this  salt 
with  chromic  chloride  and  sulphate  and  nitrate  of  chromium. 

If  the  solution  of  the  neutral  salt  is  for  some  time  digested 
with  chromic  hydrate,  it  acquires  a  darker  color,  the  acid 
reaction  disappears,  and  on  evaporating,  a  green  powder 
soluble  in  water  remains  behind.  Ordway  has  described  a 
purple  busic  salt. 

Nickel  acetate  forms  small  green  crystals  soluble  in  water, 
but  not  in  alcohol. 

Cobalt  acetate  forms  small  red  crystals,  the  concentrated 
solution  of  which  turns  blue  on  heating  but  again  red  on  cool- 
ing, and  can,  therefore,  be  used  as  sympathetic  ink. 


ACETATES    AND    THEIR    PREPARATION.  329 

Zinc  acetate,  Zn(C2H302)2. — This  salt  may  be  prepared  by 
dissolving  metallic  zinc,  zinc  oxide  or  zinc  carbonate  in  acetic 
acid,  or  by  the  decomposition  of  zinc  sulphate  by  acetates  of 
lime  or  lead  similar  to  the  acetate  of  manganese.  The  acetate 
is  in  the  first  three  instances  simply  obtained  by  evaporation, 
and  in  the  latter,  after  agitating  the  mixture,  filtering  and 
evaporating  the  filtrate.  The  salt  crystallizes  in  flexible,  opal- 
escent, six-sided  tables  which  effloresce  slightly  in  the  air. 
Technically  the  best  receipt  is  to  dissolve  4  parts  of  the  sul- 
phate of  zinc  and  7J  parts  of  acetate  of  lead  each  in  3  parts- 
of  hot  water,  mixing  the  solutions,  agitating,  and  after  the 
sulphate  of  lead  has  deposited,  drawing  the  clear  liquid  off  to- 
crystallize. 

Copper  acetates.  Cuprous  acetate,  Ca2(C2H302)2. — This  salt  is- 
produced  by  subjecting  crystallized  verdigris  to  dry  distillation. 
It  is  a  white  substance  crystallizing  in  fine  needles,  which  are 
decomposed  by  water  into  yellow  cuprous  hydrate  and  cupric 
acetate. 

With  cupric  oxide  acetic  acid  forms  a  normal  and  several 
basic  salts. 

Neutral  cupric  acetate;  crystallized  verdigris,  Cu(C2H302)2. 
— The  normal  cupric  acetate  may  be  prepared  by  dissolving 
pure  cupric  oxide  or  cupric  hydrate  in  pure  acetic  acid  or  by 
employing,  instead  of  the  pure  oxide,  copper  scales  whose  con- 
tent of  metallic  copper  and  of  cuprous  oxide  is  converted  into 
cupric  oxide  by  moistening  with  nitric  acid  and  gentle  glow- 
ing. The  cupric  oxide  thus  obtained  .is  washed  to  remove 
foreign  substances.  The  conversion  of  the  cuprous  oxide  into 
cupric  oxide  is  especially  essential  when  the  acetic  acid  is  not 
entirely  free  from  hydrochloric  acid,  as  otherwise  cuprous- 
chloride  is  formed  which  dissolves  with  difficulty. 

If  copper  scales  cannot  be  obtained,  hydrated  basic  carbon- 
ate of  copper  can  be  prepared  by  precipitating  sulphate  of 
copper  with  soda,  and,  after  washing  and  pressing,  dissolving 
in  acetic  acid.  Sulphate  of  soda  remains  dissolved  in  the 
water,  and  this  solution  can  eventually  be  utilized  for  the 


330  MANUFACTURE    OF    VINEGAR. 

conversion  of  crude  calcium  acetate  into  sodium  salt.  Instead 
of  soda,  milk  of  lime  can  also  be  used  for  the  decomposition 
of  the  sulphate  of  copper,  a  mixture  of  calcium  sulphate  and 
cupric  hydrate  being  precipitated.  By  adding  acetic  acid  the 
latter  is  redissolved  while  the  calcium  sulphate  remains  sus- 
pended. When  the  latter  has  settled  the  solution  is  drawn  off 
and  evaporated.  The  calcium  sulphate  is  repeatedly  washed 
with  small  portions  of  water,  and  the  wash-waters  are  used  for 
dissolving  fresh  quantities  of  sulphate  of  copper. 

In  case  the  sulphate  of  copper  contains  iron,  the  latter  is  re- 
moved by  digesting  the  solution  for  several  days  with  basic 
carbonate  of  copper.  The  presence  of  iron  is  recognized  by 
the  sulphate  not  dissolving  entirely  in  ammonia  in  excess,  but 
leaving  behind  a  red-brown  residue  (ferric  hydrate). 

The  neutral  acetate  can  also  be  prepared  by  dissolving  the 
basic  salt,  verdigris  (described  below),  in  acetic  acid.  The  so- 
lution is  filtered  and  evaporated  until  a  crystalline  film  is 
formed.  This  method  is,  however,  expensive. 

The  method  by  double  decomposition  may  be  recommended 
for  preparing  the  neutral  acetate  on  a  small  scale,  but  not  for 
manufacturing  purposes.  Sulphate  of  copper  (125  parts)  and 
sodium  acetate  (136  parts)  decompose  each  other,  neutral 
cupric  acetate  crystalizing  out,  while  sodium  sulphate  remains 
in  solution.  The  yield  is,  however,  somewhat  smaller  than 
theoretically  might  be  expected,  because  the  sulphate  of  cop- 
per is  not  entirely  insoluble  in  sodium  sulphate  solution.  By 
this  process  the  object  is  quickly  accomplished,  and  for  this 
reason  is  decidedly  to  be  preferred  to  the  following :  Sulphate 
of  copper  (125  parts)  and  normal  lead  acetate  (190  parts) 
decompose  completely  only  in  dilute,  but  not  in  concentrated, 
solutions.  Hence  strong  evaporation  is  required,  whereby 
acetic  acid  is  lost.  Further,  with  the  use  of  lead  acetate  some 
of  the  newly-formed  lead  sulphate  is  obtained  in  solution  ;  but 
the  lead  cannot  be  separated  with  sulphuretted  hydrogen 
because  the  latter  would  also  decompose  the  copper  salt.  The 
disadvantage  of  substituting  calcium  acetate  for  the  lead  ace- 


ACETATES    AND    THEIR    PREPARATION.  331 

tate  is  that  it  is  not  crystallized  and  hence  furnishes  no  exter- 
nal criterion  of  purity  ;  in  fact  it  always  varies  slightly  in 
composition.  If  a  small  excess  of  calcium  salt  has  been  used, 
the  latter,  after  the  calcium  sulphate  is  filtered  off  and  the 
solution  evaporated,  does  not  remain  in  the  mother  lye,  but 
crystallizes  out  as  double  salt  (see  below),  together  with  the 
copper  salt.  Since  these  acetates  create  difficulties,  and  as 
each  of  them  must  first  be  prepared  by  the  manufacturer  by 
means  of  acetic  acid,  it  would  seem  more  rational  to  directly 
use  this  acetic  acid  for  dissolving  the  cupric  oxide,  whereby 
no  by-products  of  little  value,  such  as  sulphate  of  lead,  calcium 
and  sodium,  are  formed. 

The  evaporation  of  the  solution  of  cupric  acetate  obtained 
by  any  of  the  above  methods  is  effected  in  a  copper  boiler  over 
an  open  fire,  or,  still  better,  by  steam.  It  is  recommended  to 
close  the  boiler  so  that  the  escaping  vapors  of  water  and  acetic 
acid  are  condensed  in  a  worm.  Independently  of  the  fact  that 
by  these  means  the  escaping  acetic  acid  is  regained  and  can  be 
used  for  other  purposes,  a  great  advantage  is  that  the  air  of 
the  workroom  is  thereby  not  contaminated  by  flying  particles 
of  salt. 

Crystallization  is  generally  effected  in  stoneware  pots  into 
which  dip  a  number  of  slender  wooden  rods.  The  pots  are 
placed  in  a  warm  room.  Crystallization  is  finished  in  about  14 
days.  The  crystals  turn  out  especially  beautiful  when  the  acid 
somewhat  preponderates  and  the  solution  is  cooled  very  slowly. 

The  salt  forms  dark  green  *  rhombic  prisms  of  a  nauseous 
metallic  taste,  which  dissolve  in  14  parts  of  cold,  and  5  parts 
of  boiling,  water;  and  are  also  soluble  in  alcohol.  Heated  in 
the  air  the  crystals  burn  with  a  green  flame. 

Neutral  cupric  acetate  contains  in  100  parts:  Cupric  oxide 
39.8,  anhydrous  acetic  acid  51.1,  water  9. 

On  heating,  the  dilute  solution  of  the  neutral  salt  yields 

*  There  is  also  another  salt  of  a  beautiful  blue  color,  which  contains,  however, 
o  equivalents  of  water  (VVohler).  It  is  prepared  by  exposing  a  solution  of  the  salt 
mixed  with  free  acetic  acid  to  a  low  temperature.  At  95°  F.  it  passes  into  the 
ordinary  green  salt. 


332  MANUFACTURE    OF    VINEGAR. 

acetic  acid  and  deposits  a  basic  salt ;  hence  the  use  of  strongly 
diluted  acetic  acid  or  even  distilled  vinegar  is  not  suitable  for 
the  preparation  of  crystallized  verdigris.  By  long-continued 
digestion  with  freshly  glowed  charcoal  the  dilute  solution 
yields  its  entire  content  of  copper  to  the  latter ;  hence  vinegar 
containing  copper  can  be  purified  in  this  manner  (2  or  3  per 
cent,  of  charcoal  being  sufficient).  The  crystals  of  normal 
cupric  acetate,  after  drying  in  vacuo,  lose  more  water  at  212° 
F.,  but  give  off  9  per  cent,  of  their  water  between  230°  and 
284°  F.  By  destructive  distillation  cupric  acetate  yields  strong 
acetic  acid  which  contains  acetone  and  is  contaminated  with 
copper.  Cuprous  oxide  (Cu20)  is  obtained  in  red  octahedral 
crystals  when  the  neutral  salt  is  heated  with  organic  substances, 
such  as  sugar,  honey,  starch,  etc.  „  With  the  acetates  of  potas- 
sium, sodium,  and  calcium,  normal  cupric  acetate  gives  double 
salts  of  a  vivid  blue  color,  which  form  fine  crystals. 

The  chief  use  of  normal  cupric  acetate  in  the  arts  is  in 
making  pigments  and  for  resisting  the  blue  color  which  the 
indigo  would  communicate  in  the  indigo  bath  of  the  calico 
printer.  In  the  latter  case  its  mode  of  action  depends  on  the 
readiness  with  which  it  parts  with  oxygen,  whereby  the  indigo 
is  oxidized  before  it  can  exert  any  action  on  the  cloth,  being 
itself  reduced  to  the  state  of  acetate  of  suboxide  of  copper. 
Crystallized  verdigris  is  occasionally  employed  as  a  transparent 
green  water  color  or  wash  for  tinting  maps.  In  medicine  it 
is  used  for  external  application.  It  is  poisonous,  like  all 
soluble  copper  salts. 

Basic  cupric  acetates.  Sesquibasic  cupric  acetate  (Cu(C2H302)2). 
CuO-f-  6H20. — This  compound  is  obtained  pure  by  gradually 
adding  ammonia  to  a  boiling  concentrated  solution  of  the  nor- 
mal acetate  until  the  precipitate,  which  is  at  first  formed,  is 
redissolved.  As  the  liquor  cools  the  new  salt  then  crystallizes 
out  in  beautiful  blue-green  scales,  which  at  212°  F.  lose  10.8 
per  cent,  of  their  water.  Their  aqueous  solution  is  decom. 
posed  by  boiling,  acetic  acid  being  given  off  and  the  black 
oxide  of  copper  precipitated. 


ACETATES  AND  THEIR  PREPARATION.          333 

Dibasic  cupric  acetate,  Cu(C2H302)2CuO-|-6H20,  constitutes 
the  greater  part  of  the  blue  variety  of  verdigris.  It  forms 
beautiful,  delicate,  blue,  crystalline  needles  and  scales,  which 
when  ground  form  a  fine  blue  powder.  When  heated  to  140° 
F.  they  lose  23.45  per  cent,  of  water  and  become  transformed 
into  a  beautiful  green,  a  mixture  composed  of  the  neutral  and 
tribasic  acetates.  By  repeated  exhaustion  with  water  the 
dibasic,  is  resolved  into  the  insoluble  tribasic,  salt,  and  a  solu- 
tion of  the  normal  and  sesquibasic  cupric  acetates. 

Tribasic  cupric  acetate,  Cu(C2H302)22CuO+3H20.— This  corn- 
pound  is  the  most  stable  of  all  of  the  acetates  of  copper.  It  is 
prepared  by  boiling  the  aqueous  solution  of  the  neutral  acetate, 
by  heating  it  with  alcohol,  by  digesting  its  aqueous  solution 
with  cupric  hydrate,  or  by  exhausting  blue  verdigris  with 
water  as  above  mentioned.  The  first  methods  yield  the  salt 
in  the  form  of  a  bluish  powder  composed  of  needles  and  scales, 
the  last  as  a  bright  green  powder.  This  salt  yields  all  its 
water  at  352°  F.  ;  at  a  higher  temperature  it  decomposes  and 
evolves  acetic  acid.  Boiling  water  decomposes  the  solid  triba- 
sic acetate  into  a  brown  mixture  of  the  same  salt  with  cupric 
oxide. 

Under  the  name  of  verdigris  two  varieties  of  basic  cupric 
acetates  are  found  in  commerce:  French  verdigris  which  occurs 
in  globular,  bluish-green,  crystalline  masses,  but  also  in  amor- 
phous masses,  and  English  verdigris  of  a  pure  green  color  and 
crystalline  structure,  which  is,  however,  also  manufactured  in 
Germany  and  Sweden. 

The  first  variety  is  chiefly  manufactured  in  the  region  around 
Montpellier,  France.  The  refuse  of  grapes,  after  the  extraction 
of  the  juice,  is  placed  in  casks  until  acetous  fermentation  takes 
place.  The  casks  or  vessels  are  covered  with  matting  to  pro- 
tect them  from  dirt.  At  the  end  of  two  or  three  days  the  fer- 
menting materials  are  removed  to  other  vessels  in  order  to 
check  the  process,  to  prevent  putrefaction.  The  limit  to  which 
fermentation  should  be  carried  is  known  by  introducing  a  test- 
sheet  of  copper  into  the  mass  for  24  hours;  if,  on  withdrawing 


334  MANUFACTURE  OF  VINEGAR. 

it  at  the  end  of  that  time,  it  is  found  covered  with  a  uniform 
green  coating,  the  proper  degree  of  fermentation  has  been 
reached. 

Sheets  of  copper  are  prepared  by  hammering  bars  of  the 
metal  to  the  thickness  of  about  ^  of  an  inch  (the  more  com- 
pact the  copper  sheets  the  better),  and  they  are  then  cut  into 
pieces  of  6  or  8  inches  long  by  3  to  4  broad.  Sometimes  old 
ship-sheathing  is  used  and  cut  into  pieces  of  the  required  size. 
The  sheets  are  immersed  in  a  concentrated  solution  of  verdegris 
and  allowed  to  dry.  When  the  materials  are  all  found  to  be 
in  proper  condition,  the  copper  sheets  are  laid  on  a  horizontal 
wooden  grating  in  the  middle  of  a  vat,  on  the  bottom  of  which 
is  placed  a  pan  of  burning  charcoal,  which  heats  them  to  about 
200°  F.  In  this  state  they  are  put  into  large  stoneware  jars 
with  alternate  layers  of  the  fermenting  grape  lees ;  the  vessels 
are  covered  with  straw  mats  and  left  at  rest.  At  the  end  of  10 
to  20  days  they  are  opened  to  ascertain  if  the  operation  is 
complete.  If  the  upper  layer  of  the  lees  appears  whitish  and 
the  whole  has  worked  favorably,  the  sheets  will  be  covered 
with  silky  crystals  of  a  green  color.  The  sheets  are  then  taken 
from  the  jars  and  placed  upright  in  a  cellar,  one  against  the 
other.  At  the  end  of  two  or  three  days  they  are  moistened 
with  water  and  again  placed  to  dry.  The  moistening  with 
water  is  continued  at  regular  intervals  of  a  week  for  six  or  eight 
times.  This  treatment  causes  the  sheets  to  swell  and  become 
incrusted  with  increased  coatings  of  the  copper  salt,  which  are 
detached  from  the  remainder  of  the  sheets  by  a  copper  knife. 
The  scraped  plates  are  submitted  to  a  fresh  treatment  till  the 
whole  of  the  copper  is  converted  into  verdigris.  The  salt 
scraped  off  is  made  into  a  consistent  paste  by  kneading  with  a 
little  water,  and  in  this  state  is  packed  into  leathern  bags  which 
are  placed  in  the  sun  to  dry  until  the  mass  hardens  and  forms 
the  tough  substance  which  constitutes  the  commercial  article. 

In  England,  Germany  and  Sweden  copper  sheets  are  moist- 
ened with  a  solution  of  verdigris  in  vinegar  and  placed  in  a 
warm  room,  or  woollen  cloths  moistened  with  the  above  solu- 


ACETATES  AND  THEIR  PREPARATION.          335 

tion  are  used,  which  are  placed  alternately  with  the  copper 
sheets  in  a  square  wooden  box.  The  woollen  cloths  are  moist- 
ened with  the  solution  every  three  days  for  12  or  15  days, 
when  small  crystals  commence  to  form  on  the  sheets.  The 
sheets  are  then  drawn  every  six  days  through  water  and  re- 
placed in  the  box,  but  not  in  direct  contact  with  the  woollen 
cloths,  small  disks  of  copper  or  small  pieces  of  wood  being 
placed  between  each  cloth  and  sheet.  The  woollen  cloths  are 
now  more  thoroughly  saturated  than  before,  but  with  a  weakei 
solution.  With  a  temperature  of  from  54°  to  59°  F.,  6  to  8 
weeks  are  required  before  the  verdigris  can  be  scraped  off. 
The  product  is  not  identical  with  that  obtained  by  the  French 
method,  it  being  somewhat  poorer  in  acetic  acid,  and  hence  its 
color  is  not  bluish-green,  but  almost  pure  green. 

Lead  Acetates. — With  plumbic  oxide  acetic  acid  gives  a 
neutral,  as  well  as  several  basic,  salts.  The  most  important  of 
these  combinations  are  the  neutral  salt,  known  in  commerce 
as  sugar  of  lead,  and  a  basic  salt  by  means  of  which  white 
lead  is  obtained. 

Neutral  Acetate  of  Lead  (Sugar  of  Lead),  Pb(C2H302)2+3HO. 
— According  to  Volkel's  method,  acetic  acid  prepared  from 
wood-vinegar  and  rectified  over  potassium  dichromate  is  satu- 
rated with  litharge,  filtered  or  decanted,  and  after  a  further 
addition  of  acetic  acid  until  a  slightly  acid  reaction  takes  place, 
evaporated  to  the  crystallizing  point. 

By  saturating  acetic  acid  with  litharge,  a  solution  of  basic 
salt  is  obtained,  which  is  later  on  converted  into  neutral  salt 
by  the  addition  of  acetic  acid.  This  is  more  suitable  than 
using  only  as  much  litharge  as  the  acetic  acid  requires  for 
the  formation  of  the  neutral  salt,  because  the  litharge  dis- 
solves with  greater  ease  in  solution  of  sugar  of  lead  than  in 
acetic  acid. 

Solution  of  sugar  of  lead,  like  solution  of  neutral  cupric  ace- 
tate, permits  of  the  evaporation  of  acetic  acid  in  boiling  ;  and, 
hence,  it  is  best  to  use  strong  acetic  acid,  because  less  will  have 
to  be  evaporated  and  the  loss  of  acetic  acid  be  consequently 


336  MANUFACTUKE    OF    VINEGAR. 

smaller.  By  taking,  for  instance,  acetic  acid  of  1.057  specific 
gravity,  for  100  Ibs.  of  it  82  Ibs.  of  litharge  are  required  for  the 
formation  of  the  neutral  salt.  A  larger  quantity  is,  however, 
taken  (from  100  to  180  Ibs.),  so  that  a  basic  salt  is  formed,  or, 
with  100  Ibs.,  a  mixture  of  neutral  and  basic  salts.  To  recog- 
nize the  point  of  neutralization  in  the  subsequent  addition  of 
acetic  acid,  litmus  paper  is  used,  or,  still  better,  dilute  solution 
of  corrosive  sublimate  (1  part  of  corrosive  sublimate  in  100  of 
water),  which  does  not  change  the  neutral  salt,  but  produces 
turbidity  in  the  basic  (Buchner).  Hence,  by  from  time  to 
time  testing  the  lead  solution  with  this  reagent,  the  point  of 
neutralization  is  reached  the  moment  turbidity  ceases.  This 
test  is  better  than  with  litmus,  considerable  experience  being 
required  to  hit  the  right  point  with  the  latter  on  account  of 
solution  of  sugar  of  lead  showing  a  slight,  but  perceptible  acid 
reaction. 

The  solution  of  litharge  in  acetic  acid  is  promoted  by  heat, 
and  is  effected  either  in  a  copper  pan,  the  bottom  and  sides  of 
which  are  brought  in  contact  with  a  few  bright  sheets  of  lead 
(to  prevent  the  copper  from  being  attacked),  or  in  a  lead  pan 
over  an  open  fire,  or  in  a  wooden  vat  into  which  steam  is  in- 
troduced. The  clear  solution  is  evaporated.  If  this  is  to  be 
done  over  an  open  fire,  it  is  recommended  to  have  a  prepara- 
tory heating  pan  for  each  evaporating  pan,  as  described  in  the 
preparation  of  calcium  acetate,  the  preparatory  heating  pan, 
which  is  heated  by  the  escaping  gases,  being  used  for  the  solu- 
tion of  the  litharge  in  acetic  acid.  Lead  pans,  if  used,  should 
rest  upon  strong  cast-iron  plates.  The  dimensions  of  the  pans 
vary  very  much.  According  to  Assmus,  they  are  6J  feet  long, 
4  feet  wide,  and  from  12  to  14  inches  deep,  while  the  depth 
of  the  preparatory  heating  pans  is  from  24  to  28  inches.  From 
the  latter,  which  stand  at  a  higher  level,  the  clear  solution  is 
discharged,  through  a  stop-cock  just  above  the  bottom,  into 
the  evaporating  pans.  Evaporation  should  be  effected  at  a 
moderate  heat;  actual  boiling  must  be  strictly  avoided,  as 
otherwise  large  losses  of  acetic  acid  are  unavoidable  and  the 
solution  readily  acquires  a  yellow  coloration. 


ACETATES    AND    THEIR    PREPARATION.  337 

According  to  the  degree  of  evaporation  (to  36°  B.  or  to  46° 
B.  or  more)  of  the  sugar  of  lead  solution,  distinct  crystals  are 
obtained  or  only  a  radiated  crystalline  mass.  With  a  perfectly 
pure  solution  the  first  method  is  the  best,  since  crystals  bring 
a  better  price.  The  mother-lye,  after  being  again  acetified,  is 
once  more  evaporated  and  acetified  and  yields  more  crystals. 

Stein  recommends  the  conducting  of  the  vapors  of  acetic 
acid  or  of  vinegar  into  litharge  mixed  with  a  very  small  quan- 
tity of  water.  This  method  is  in  general  use  in  Germany.  But 
as  the  extract  remaining  iri-the  still  retains  a  considerable 
quantity  of  acetic  acid,  especially  if  beer  had  been  added  to  the 
liquid  used  in  the  preparation  of  the  vinegar,  it  is  advisable  to 
increase  the  boiling  point  of  the  latter  by  the  addition  of  one- 
third  of  its  weight  of  common  or  rock  salt.  At  first  the  water 
condenses  in  the  receiver  and  the  volume  of  the  fluid  containing 
the  litharge  increases,  but  when  the  boiling  point  is  reached  in 
the  condensing  vessels,  only  the  acetic  acid  is  retained,  while 
the  litharge  is  first  converted  into  sexbasic  and  then  into  tri- 
basic  acetate.  To  obtain  neutral  salt,  however,  either  the 
vapors  must  be  somewhat  expanded  or  several  condensing 
vessels  be  placed  one  after  the  other. 

Fig.  84  shows  the  distilling  apparatus,  consisting  of  a  still, 
a,  of  sheet-copper.  The  vapors  pass  through  a  copper  pipe,  5, 
into  the  wooden  vat,  c,  lined  with  lead,  and  about  35  inches 
in  diameter  and  (>7  inches  deep.  In  this  vat  are  four  bottoms, 
d,  of  thick  lead  provided  with  fine  perforations.  Short  lead 
pipes,  soldered  into  these  bottoms  and  arranged  as  shown  in 
the  figure,  serve  to  conduct  the  vinegar  vapors  in  the  vat  to 
and  fro  in  the  interspaces  between  the  lead  bottoms.  For  each 
still  at  least  three  of  such  vats  are  connected  with  each  other. 
Upon  the  lead  bottoms  is  first  placed  a  layer  of  linen  or  of 
flannel,  and  next  a  layer  of  litharge  2  to  4  inches  deep.  To 
prevent  the  litharge  from  packing,  it  is  mixed  with  an  equal 
volume  of  pebbles,  about  the  size  of  a  pea.  The  vats  are  pro- 
vided with  lids  of  sheet-copper  lined  with  lead.  From  the  lid 
of  the  last  vat  a  pipe  leads  to  a  worm  surrounded  with  cold 
22 


338  MANUFACTURE  OF  VINEGAR. 

water.  The  stop-cocks  on  the  bottoms  of  the  vats  permit  the 
discharge  of  the  collected  lead  solution,  which  is  effected  (with 
the  use  of  acetic  acid)  when  it  shows  a  specific  gravity  of  at 
at  least  36°  Be.  The  solution  being,  however,  basic,  it  is  aceti- 
fied with  strong  acetic  acid,  and  brought  into  the  crystallizing 

vessels. 

This  method  is  decidedly  the  best,  because  the  evaporation 
of  the  solution  is  entirely  or  almost  entirely  omitted  and  the 
air  of  the  workroom  is  not  contaminated  by  particles  of  sugar 
of  lead,  which  is  very  injurious  "to  the  health  of  the  workmen. 


FIG.  84. 


Furthermore,  this  taethod  does  not  require  the  use  of  pure 
acetic  acid,  since  the  impurities  remain  in  the  still.  This,  how- 
ever, holds  good  only  for  non-volatile  impurities.  For  the 
production  of  colorless  salt,  the  crude  acetic  acid  from  wood- 
vinegar  must  necessarily  be  purified,  as  above  mentioned, 
by  potassium  chromate  and  sulphuric  acid. 

The  crystallizing  pans  are  either  of  stone-ware  or  of  wood 
lined  with  lead  or  thin  copper,  to  which  is  soldered  a  strip  of 
lead  down  the  sides  and  across  the  bottom,  with  the  idea  of 
rendering  the  metal  more  electro-negative,  so  as  to  prevent  the 


ACETATES    AND    THEIR    PREPARATION. 


339 


acetic  acid  from  acting  on  it.  The  wooden  crystallizing  pans 
are  about  4  feet  long  by  2  feet  wide,  and  from  G  to  8  Indies 
deep,  sloping  inwards  at  the  edges.  Shallow,  slightly  conical 
copper  vessels.  6  inches  deep,  with  a  diameter  of  29J  inches 
at  the  bottom  and  31 J  inches  at  the  top,  are  also  used.  The 
stone-ware  pans  are  placed  upon  a  slightly  inclined  level  cov- 
ered with  lead.  In  these  small  pans  crystallization  is  complete 
in  24  hours,  while  from  48  to  72  hours  are  required  with  the 
use  of  the  larger  wooden  vessels.  Crystallization  being  com- 
plete, the  mother-lye  is  removed,  and  the  vessels  are  placed 
upon  a  wooden  frame  over  a  gutter  of  sheet-lead  to  drain  off, 
as  shown  in  Figs.  85  and  8G. 


FIG.  85. 


FIG.  86. 


If  especially  beautiful  crystals  are  to  be  obtained,  the  first 
crystals,  which  are  not  very  distinct,  are  again  dissolved  in 
the  water  obtained  by  the  condensation  of  the  vapors  escaping 
from  the  still.  The  solution  being  evaporated  to  the  proper 
density  is  again  allowed  to  crystallize.  The  crystals,  after 
sufficient  drainage,  are  placed  upon  linen  spread  over  wooden 
hurdles  and  dried  at  a  moderate  heat,  not  exceeding  75°  F. 
In  some  factories  the  heated  air  of  a  stove,  placed  outside  the 
drying-house,  is  conveyed  through  pipes  passing  round  the 
interior;  at  other  places  steam  heat  is  employed  for  this  pur- 
pose, which  is  much  to  be  preferred,  on  account  of  its  being 
more  easily  regulated. 

When  working  on  a  large  scale  a  centrifugal  is  advantage- 
ously employed  for  the  separation  of  the  mother-lye,  in  the 


340  MANUFACTURE    OF    VINEGAR. 

same  manner  as  recommended  for  the  preparation  of  sodium 
acetate. 

Litharge  being  a  quite  impure  lead  oxide  never  dissolves 
entirely,  and  frequently  contains  over  10  per  cent,  of  impuri- 
ties, consisting  of  sand,  clay,  red  lead  or  minium  (Pb304), 
metallic  lead,  traces  of  silver,  cupric  and  ferric  oxides.  The 
cupric  oxide  passes  into  the  sugar  of  lead  solution  and  colors 
it  slightly  blue.  To  separate  the  copper,  bright  sheets  of  lead 
are  dipped  into  the  solution,  the  copper  separating  upon  them 
in  the  form  of  a  dark  slime.  The  sheets  of  lead  must  be  fre- 
quently cleansed  (scraped),  as  otherwise  they  lose  their  effect. 
When  there  is  a  large  accumulation  of  litharge  residue,  it  can 
be  worked  for  silver. 

Sugar  of  lead  can  also  be  prepared  from  metallic  lead,  the 
process  having  been  recommended  first  by  Berard,  and  is  said 
by  Runge  to  yield  a  good  product  with  great  economy.  Gran- 
ulated lead,  the  tailings  in  the  white  lead  manufacture,  etc., 
are  put  in  several  vessels,  say  eight,  one  above  the  other,  upon 
steps,  so  that  the  liquid  may  be  run  from  one  to  the  other. 
The  upper  one  is  filled  with  acetic  acid,  and  after  half  an  hour 
let  off  into  the  second,  after  another  half  hour  into  the  third, 
and  so  on  to  the  last  or  eighth  vessel.  The  acid  causes  the 
lead  to  absorb  oxygen  so  rapidly  from  the  air  as  to  become 
hot.  When  the  acid  runs  off  from  the  lowest,  it  is  thrown  on 
the  uppermost,  vessel  a  second  time  and  carries  off  the  acetate 
of  lead  formed.  After  passing  through  the  whole  series  the 
solution  is  so  strong  that  it  may  be  evaporated  at  once  so  as  to 
crystallize. 

Apparently  this  method  has  a  considerable  advantage  over 
that  with  litharge,  metallic  lead  being  cheaper  and  producing 
more  sugar  of  lead  (entirely  free  from  copper)  than  litharge, 
because  103.5  Ibs.  of  pure  lead  yield  189.5  Ibs.  of  sugar  of  lead, 
while  the  same  quantity  is  only  obtained  from  111.5  Ibs.  of  pure 
litharge.  Furthermore,  commercial  lead  is  always  purer  than 
litharge.  On  the  other  hand,  this  process  has  the  disadvan- 
tage of  a  considerable  quantity  of  acetic  acid  being  lost  by 


ACETATES    AND    THEIR    PREPARATION.  341 

evaporation  on  account  of  it  having  to  pass  through  several 
vessels.  The  manufacture  of  sugar  of  lead  is  most  suitably 
combined  with  that  of  white  lead,  it  being  thus  possible  to 
utilize  the  tailings,  etc.,  to  greater  advantage  than,  as  is  fre- 
quently done,  by  melting  them  together  and  remelting,  which 
always  causes  considerable  loss. 

Sugar  of  lead  is  further  formed  by  boiling  lead  sulphate 
with  a  very  concentrated  solution  of  barium  acetate,  barium 
sulphate  (permanent  white)  being  thereby  precipitated.  For 
100  parts  of  lead  sulphate  84  parts  of  anhydrous  or  100  of 
crystallized  barium  acetate  are  required,  the  yield  being  125 
parts  of  sugar  of  lead.  Sulphate  of  lead  is  obtained  in  large 
quantities  as  a  by-product  in  the  preparation  of  aluminium 
acetate. 

For  many  purposes  of  dyeing  and  printing  the  use  of  pure 
sugar  of  lead  is  not  necessary,  the  brown  acetate  of  lead  an- 
swering all  requirements.  For  its  preparation  ground  litharge 
is  introduced  in  small  portions,  stirring  constantly,  into  dis- 
tilled wood  vinegar  in  a  vat  until  red  litmus  paper  is  colored 
blue,  and,  hence,  a  basic  salt  is  formed.  The  impurities  sep- 
arating on  the  surface  are  removed  and  the  clear  fluid  is  then 
transferred  to  a  copper  pan  equipped  with  strips  of  lead,  and  is 
evaporated  to  about  two-thirds  its  volume,  the  brown  smeary 
substances  rising  to  the  surface  during  evaporation  being  con- 
stantly removed.  By  again  diluting  and  slightly  acidulating 
the  concentrated  fluid  a  further  portion  of  the  foreign  sub- 
stances can  be  removed.  Finally  evaporation  is  carried  to 
the  crystallizing  point,  i.  e.,  until  a  few  drops  congeal  when 
allowed  to  fall  upon  a  cold  metal  plate.  The  addition  of 
animal  charcoal  for  the  purpose  of  discoloration  is  of  no  ad- 
vantage. The  coloration  is  not  completely  removed,  and  the 
little  effect  produced  is  attained  at  a  considerable  loss  of  salt, 
which  is  absorbed  by  the  animal  charcoal. 
.  By  disturbing  crystallization  by  constant  stirring  during 
cooling,  a  nearly  amorphous  mass,  having  the  appearance  of 
yellow  wax,  is  obtained,  which  is  much  liked  by  many  con- 


342  MANUFACTURE    OF    VINEGAR. 

sutners.  The  product  thus  obtained  is  not  always  a  neutral 
salt,  but  sometimes  a  mixture  of  neutral  and  basic  salts  (be- 
sides empyreumatic  substances).  After  cooling  it  must,  there- 
fore, be  quickly  and  well  packed,  in  order  to  protect  it  from  the 
moisture  and  the  carbonic  acid  of  the  air.  The  sugar  of  lead 
solution  may,  however,  also  be  evaporated  only  so  far  that 
some  mother-lye  remains  after  cooling,  the  crystallized  mass 
being  then  for  some  time  allowed  to  stand  in  a  moderately 
warm  room.  In  consequence  of  capillarity,  the  impurities, 
which  occur  chiefly  in  the  mother-lye,  gradually  rise  up  be- 
tween the  crystals,  a  slight  coating  of  yellow,  or  brown,  smeary 
substance  being  finally  formed  upon  the  mass  of  crystals, 
which  can  be  readily  removed. 

The  linen  upon  which  the  crystals  are  dried  must  be  care- 
fully protected  from  fire,  as  it  ignites  from  the  slightest  spark 
and  burns  like  tinder. 

If  the  hot  solution  be  set  aside  to  cool  rapidly,  the  sugar  of 
lead  crystallizes  in  clusters  of  fine  needles  ;  but  if  evaporation 
be  conducted  slowly  the  crystals  are  truncated  and  flattened, 
quadrangular  and  hexahedral  prisms  derived  from  a  right 
rhombic  prism.  Acetate  of  lead  has  a  sweet  astringent  taste, 
is  soluble  in  1 J  parts  of  water  and  in  8  parts  of  ordinary  alco- 
hol. The  crystals  are  permanent  in  the  atmosphere,  but  are 
apt  to  effloresce  and  become  anhydrous  if  the  temperature 
ranges  between  70°  and  100°  F. 

Acetate  of  lead  consists  of: 

Plumbic  oxide 58.9 

Anhydrous  acetic  acid 26.9 

Water  .  .    .    14.2 


100.00 


Aqueous  solution  of  sugar  of  lead  slightly  reddens  litmus- 
paper,  but  shows  an  alkaline  reaction  upon  turmeric,  brown- 
ing it. 

At  167°  F.  the  crystals  of  acetate  of  lead  melt,  and  slowly 
yield  up  their  water ;  by  heating  the  entirely  dephlegmated 


ACETATES    AND    THEIR    PREPARATION.  343 

salt  more  strongly  it  fuses  at  536°  F.  to  a  clear,  oil-like,  color- 
less fluid  and  decomposes  above  this  temperature,  evolving  all 
the  compounds  usually  obtained  in  the  destructive  distillation 
of  the  acetates  of  the  heavy  metals,  while  a  residue  of  metallic 
lead  in  a  very  minute  state  of  division,  with  some  charcoal,  is 
left  behind.  When  this  distillation  is  conducted  in  a  glass 
tube  closed  at  one  end  and  having  the  other  drawn  out  for 
convenience  of  sealing  at  the  end  of  the  operation,  the  well- 
known  lead  pyrophorous  is  made.  The  particles  of  metallic 
lead  are  so  small  that,  when  thrown  into  the  air,  oxygen  mole- 
cules come  into  such  intimate  contact  with  them  that  ignition 
is  effected  from  the  rapidity  with  which  lead  oxide  is  formed. 

A  slight  decomposition  occurs  when  the  neutral  salt  is  ex- 
posed to  an  atmosphere  of  carbonic  acid,  carbonate  of  lead 
being  formed  ;  the  portion  of  acetic  acid  thus  liberated  pro- 
tects the  remainder  from  further  change. 

Cold  solution  of  sugar  of  lead  is  not  immediately  changed 
by  ammonia  ;  by  adding,  however,  a  large  excess  of  it,  sexbasic 
acetate  of  lead  is  gradually  separated  ;  on  boiling,  yellow-red 
crystalline  lead  oxide  is  precipitated. 

The  introduction  of  chlorine  gas  into  a  solution  of  sugar  of 
lead  produces  in  a  short  time  a  brown  precipitate  of  plumbic 
dioxide.  Bromine  acts  in  a  similar  manner,  but  on  account 
of  its  insolubility,  iodine  produces  scarcely  any  effect. 

Solution  of  calcium  chloride  at  once  produces  a  yellow 
precipitate,  which  gradually  becomes  brown. 

Sugar  of  lead  containing  considerable  copper  has  a  bluish 
appearance.  If  the  content  of  copper  is  small,  it  is  recognized 
by  the  solution  acquiring  with  ammonia  a  blue  coloration,  or, 
still  better,  by  mixing  the  solution  of  sugar  of  lead  with  an  ex- 
cess of  solution  of  Glauber's  salt  and  testing  the  filtrate  with 
potassium,  ferrocyanide.  A  dark-red  precipitate  indicates 
copper. 

Sugar  of  lead,  as  well  as  the  basic  lead  salts  to  be  men- 
tioned further  on,  possesses  poisonous  properties. 

Sugar  of  lead  is  chiefly  used  for  the  preparation  of  alum- 


344  MANUFACTURE    OP    VINEGAK. 

inium  acetate,  as  well  as  of  other  acetates.  Considerable 
quantities  of  it  are  consumed  in  the  manufacture  of  colors,  for 
instance,  of  neutral  and  basic  lead  chromate,  chrome  yellow, 
chrome  orange,  and  chrome  red.  Upon  the  cloth-fibre  (espec- 
ially wool)  chrome  yellow  and  chrome  orange  are  produced 
by  means  of  sugar  of  lead,  particularly  with  the  brown  variety  ; 
the  latter  product  being  also  very  suitable  for  the  production 
of  the  so-called  chrome  green,  which  is  obtained  by  the  joint 
precipitation  of  chrome  yellow  and  Berlin  blue. 

Neutral  lead  acetate  gives  crystallizable  double  salts  with 
potassium  acetate  and  sodium  acetate  as  well  as  with  lead 
nitrate,  lead  chloride,  lead  bromide,  etc. 

Basic  lead  acetates. — Several  of  these  compounds  are  known. 
Those  with  2  and  3  equivalents  of  lead  oxide  to  1  equivalent 
of  acetic  acid  are  soluble  in  water,  show  a  strong  alkaline  reac- 
tion, and  with  carbonic  acid  the  solutions  yield  at  once  and 
in  every  degree  of  concentration,  abundant  precipitates  of 
white  lead  (basic  carbonate  of  lead),  while,  when  the  operation 
is  at  a  suitable  moment  interrupted,  neutral  salt  remains  in 
solution.  In  this  manner  white  lead  is  manufactured  accord- 
ing to  the  so-called  French  method  (of  Thenard  and  Hoard) 
at  Clichy  and  other  places  in  France,  as  well  as  in  different 
German  factories.  If  however,  the  introduction  of  carbonic 
acid  be  continued  until  no  more  precipitate  is  formed,  a  part 
of  the  lead  of  the  neutral  salt  is  also  precipitated  as  carbonate, 
which,  however,  is  neutral,  and  an  acid  solution  remains 
behind. 

The  soluble  salt  known  as  lead  vinegar  or  extract  of  lead  is 
prepared  by  digesting  2  parts  of  sugar  of  lead  dissolved  in  5 
of  water  with  1  of  finely  powdered  litharge.  The  propor- 
tional quantities  of  sugar  of  lead,  litharge  and  water  prescribed 
by  the  Pharmacopoeias  of  the  different  countries  vary  very 
much,  and,  consequently,  also,  the  compositions  and  specific 
gravities  (from  1.20  to  1.36)  of  the  solutions  of  lead  prepared 
in  accordance  with  them.  The  litharge  dissolves  very  readily 
in  the  sugar  of  lead  solution,  in  fact  with  greater  ease  than  in 


ACETATES  AND  THEIR  PREPARATION.          345 

acetic  acid,  and  especially  with  greater  rapidity  if  the  sugar  of 
lead  solution  be  heated  in  a  silver  dish  to  the  boiling  point 
and  the  litharge  gradually  introduced.  For  the  manufacture 
on  a  large  scale,  the  sugar  of  lead  solution  and  the  litharge 
may  be  brought  into  a  barrel  revolving  around  its  axis.  If 
the  operation  is  to  be  conducted  at  the  ordinary  temperature, 
the  barrel  must  be  closed  to  prevent  the  access  of  the  car- 
bonic acid  of  the  air.  Very  remarkable  is  the  behavior  of  the 
tribasic  acetate  towards  hydrogen  dioxide ;  plumbic  dioxide 
being  first  formed.  But  in  a  short  time  this  exerts  a  decom- 
posing influence  upon  the  hydrogen  dioxide  which  may  be 
present  in  excess,  so  that  both  dioxides'  now  lose  one-half  of 
their  oxygen,  which  evolves  in  the  form  of  gas,  and  water 
and  plumbic  oxide  are  formed.*  Now,  as  freshly  precipitated 
plumbic  dioxide  possesses  the  further  property  of  decomposing 
solution  of  potassium  iodide,  Schoenbein  recommends  tribasic 
acetate  of  lead,  together  with  paper  coated  with  paste  prepared 
with  potassium  iodide,  as  the  most  sensitive  reagent  for  hydro- 
gen dioxide. 

Lead  Sesquibasic  Acetate,  Triplumbic  Tetracetate. — This  salt  is 
obtained  by  heating  the  diacetate  until  it  becomes  a  white, 
porous  mass ;  this  is  redissolved  in  water  and  set  aside  to 
crystallize.  Sesquibasic  acetate  is  soluble  in  both  water  and 
alcohol ;  its  solutions  are  alkaline. 

Tribasic  acetate  of  lead  is  prepared  by  digesting  189.5  Ibs.  of 
sugar  of  lead  with  223  Ibs.  of  plumbic  oxide  (pure)  or  3  Ibs. 
of  sugar  of  lead  to  4  Ibs.  of  litharge ;  or,  according  to  Payen, 
into  100  volumes  of  boiling  water  are  poured  100  volumes  of 
aqueous  solution  of  sugar  of  lead  saturated  at  86°  F.,  and 
afterwards  a  mixture  of  pure  water  at  140°  F.,  with  20  volumes 
of  ammonia  liquor  free  from  carbonate.  The  vessel  is  then 
immediately  closed,  and  in  a  short  time  an  abundance  of  the 
tribasic  acetate  crystallizes  out.  The  salt  presents  itself  under 
the  form  of  long  needles.  It  is  insoluble  in  alcohol,  very  solu- 

*  Schoenbein  in  Wagner's  Jahresbericht,  1862. 


346  MANUFACTURE    OF    VINEGAR. 

ble  in  water,  its  solution  being  alkaline.  Tribasic  acetate  is 
the  most  stable  of  all  the  subacetates  of  lead.  It  takes  a  lead- 
ing part  in  the  manufacture  of  white  lead  by  the  Clichy  pro- 
cess. It  is,  in  point  of  fact,  a  solution  of  this  salt,  which  is 
decomposed  by  the  carbonic  acid,  and  gives  rise  to  the  carbon- 
ate of  lead,  being  itself  at  the  same  time  converted  into  lead 
diacetate.  In  the  Dutch  process  the  formation  of  lead  carbon- 
ate is,  according  to  Pelouze,  also  due  to  the  formation  of  tri- 
basic  acetate  on  the  surface  of  the  sheets  of  lead,  which  is,  in 
its  turn,  decomposed  by  the  carbonic  acid. 

Sexbasic  Acetate  of  Lead. — This  body  is  prepared  by  digest- 
ing any  of  the  preceding  salts  with  lead  oxide.  It  is  a  white 
powder  slightly  soluble  in  boiling  water,  from  which  it  crys- 
tallizes out  in  silky  needles  which  consist  of  two  equivalents 
of  the  salt  combined  with  three  equivalents  of  water. 

Uranium  Acetate. — With  uranous  oxide,  acetic  acid  combines 
to  a  dark  green  crystallizable  salt,  and  with  uranic  oxide  to  a 
yellow  basic  salt,  which,  combined  with  water,  appears  in  two 
different  forms  of  crystals.  It  is  remarkable  for  giving,  with 
many  other  acetates,  well  crystallizing  salts,  of  a  beautiful 
color,  and  partly  showing  magnificent  dichroism  (Wertheim 
and  Weselsky). 

Tin  acetate  is  prepared  by  dissolving  stannous  hydrate  *  in 
heated  strong  acetic  acid,  or  by  mixing  stannous  chloride 
(SnCl2)  with  acetate  of  sodium  or  calcium.  It  forms  small 
colorless  needles,  which  have  a  strong  metallic  taste  and 
readily  decompose  in  the  air.  The  salt  is  used  to  discharge 
azo-dyestuffs  in  calico  printing. 

Bismuth  Acetate. — Bismuth  nitrate  prepared  by  gradually 
introducing  pulverized  metallic  bismuth  into  cold  dilute  nitric 
acid  is  mixed  with  pure  concentrated  sugar  of  lead  solution. 
The  salt  separates  in  small,  colorless  needles. 

Mercurous  acetate  can  be  prepared   by  dissolving  pure  mer- 

*The  hydrate  is  obtained  by  precipitating  stannous  chloride  with  soda  lye  and 
washing  the  precipitate. 


ACETATES  AND  THEIR  PREPARATION.  347 

curous  oxide  or  its  carbonate  in  acetic  acid,  or  by  mingling 
hot  solutions  of  mercurous  nitrate  and  acetate  of  sodium  or  of 
potassium.  The  pure  mercurous  carbonate  is  heated  to  boiling 
with  8  parts  of  water,  and  concentrated  acetic  acid  added  until 
all  is  dissolved  ;  the  hot,  filtered  liquid  free  from  oxide  being 
allowed  to  cool.  Or,  acidulated  nitrate  is  diluted  with  6  to  8 
parts  of  water,  heated  and  mixed  with  one  equivalent  of  acetate 
of  sodium  or  potassium,  dissolved  in  8  parts  hot  water  con- 
taining a  little  free  acid,  and  cooled.  The  salt,  when  sepa- 
rated, is  washed  with  a  little  cold  water,  dried  in  the  dark  at 
a  gentle  heat,  and  kept  from  the  light  in  covered  bottles. 

It  crystallizes  in  fine,  white,  silvery  scales,  flexible  and  unc- 
tuous to  the  touch,  with  a  nauseous  metallic  taste,  easily  de- 
composed by  light.  It  dissolves  with  difficulty  in  cold  water, 
requiring  33  parts  at  the  ordinary  temperature.  It  is  par- 
tially decomposed  by  boiling  water  into  acid  and  basic  salts  of 
both  oxides  and  metallic  mercury.  It  is  used  in  pharmacy. 

Mercuric  Acetate. — Dissolve  red  oxide  of  mercury  in  concen- 
trated acetic  acid  at  a  gentle  heat  and  evaporate  to  dry  ness, 
or  partially  to  crystallization,  or  by  spontaneous  evaporation. 
When  obtained  by  the  first  process  it  is  a  white  saline  mass ; 
by  the  second  it  forms  crystalline  scales;  and  by  the  third, 
four-sided  plates,  which  are  partly  transparent,  partly  pearly 
and  translucent,  anhydrous,  of  a  nauseous  metallic  taste,  fusi- 
ble without  decomposition,  solidifying  to  a  granular  mass,  but 
the  point  of  decomposition  of  the  latter  is  near  that  of  fusion. 
It  dissolves  in  4  parts  of  water  at  50°  F.,  in  2.75  at  66.2°  F., 
and  in  1  at  212°,  but  by  boiling  it  is  partly  decomposed, 
red  oxide  being  separated.  Even  in  the  air  its  solution  suf- 
fers the  latter  change  and  contains  a  basic  salt.  With  free 
acetic  acid  it  is  not  decomposed.  One  hundred  parts  of  alco- 
hol dissolve  5f  of  this  salt,  and  this  solution  behaves  like  the 
aqueous  one.  It  generally  contains,  except  when  carefully 
crystallized,  some  mercurous  oxide. 

Silver  Acetate. — This  salt  is  obtained  by  precipitating  a  con- 
centrated solution  of  silver  nitrate  with  a  concentrated  solution 


348  MANUFACTURE    OF    VINEGAR. 

of  sodium  acetate.  It  forms  a  white  crystalline  precipitate. 
ft  dissolves  in  about  100  parts  of  cold,  but  readily  in  hot, 
water,  and  only  sparingly  in  alcohol.  On  exposure  to  light  it 
acquires  a  dark  color,  being  partially  reduced.  On  heating, 
it  yields  acetic  acid,  metallic  silver  remaining  behind. 

If  the  salt  be  heated  with  disulphide  of  carbon  in  a  closed 
glass  tube  to  329°  F.,  silver  sulphide,  carbonic  acid  and  anhy- 
drous acetic  acid  are  formed  (Broughton). 

On  treating  the  dry  salt  with  iodine,  lively  decomposition 
takes  place,  whereby  silver  iodide,  some  metallic  silver  and  coal 
remain  behind,  while  methyl  oxide,  acetic  acid,  acetylene  and 
hydrogen  appear.  With  iodine  a  solution  of  this  salt  yields 
acetic  acid,  silver  iodide  and  iodate  of  silver  (Birnbaum). 


CHAPTER  XXVI. 

PREPARATION  OF  PURE  WOOD  SPIRIT  OR  METHYL  ALCOHOL,  AND 
OF  ACETONE,  AND  WORKING  THE  WOOD  TAR. 

Preparation  of  Wood  Spirit. — The  crude  wood-spirit  solu- 
tions collected  during  the  distillation  of  the  wood  vinegar 
contain,  according  to  their  method  of  production,  from  9  to  10 
per  cent,  wood  spirit.  They  are  subjected  to  repeated  distil- 
lation and  rectification  over  milk  of  lime  to  fix  the  acetic  acid 
present  and  to  saponify  the  methyl  acetate.  In  this  manner 
wood  spirit  is  produced,  i.  e.}  a  mixture  that  besides  methyl 
alcohol  contains  other  combinations  such  as  aldehyde,  methyl- 
acetic  ether,  acetone  and  similar  combinations,  amines,  higher 
alcohols,  etc. 

The  crude  wood-spirit  of  commerce  contains  besides  the 
above-mentioned  constituents.  75  per  cent,  of  methyl  alcohol. 
It  is  clear  as  water  to  dark  brown  and  can  be  mixed  in  every 
proportion  with  water  without  becoming  turbid. 

Wood  spirit  for  denaturing  purposes  is  produced  from  the 


PREPARATION    OF    PURE    WOOD    SPIRIT.  349 

crude  wood  spirit  by  further  rectification.  It  contains  95  per 
cent,  methyl  alcohol,  and  while  the  higher  alcohols  and  the 
acetone  have  been  removed,  aldehyde,  methyl  acetate,  etc., 
are  still  present. 

Pure  wood  spirit  contains  98  to  99.5  per  cent,  wood-spirit 
constituents,  among  which  methyl  alcohol,  however,  pre- 
ponderates so  that  they  are  almost  entirely  pure.  Such  pure 
wood  spirit  contains  only  very  small  quantities  of  acetone— 
0.01  to  0.5  per  cent.  It  does  not  discolor  bromide  solution 
and  when  mixed  with  concentrated  sulphuric  acid  acquires  an 
only  slightly  yellower  color. 

The  rectification  of  the  crude  wood-spirit  solutions  collected 
during  the  distillation  of  the  wood  vinegar  is  effected  in  a 
columnar  still.  The  crude  wood-spirit  solution  is  brought 
into  the  still  and,  after  adding  slaked  lime,  the  fluid  is  allowed 
to  rest  for  several  hours.  After  the  addition  of  the  lime  the 
fluid  soon  becomes  strongly  heated  in  consequence  of  the  free 
acids  combining  with  the  lime,  and  of  the  formation  of  cal- 
cium acetate  and  methyl  alcohol  from  the  methyl  acetic  ether, 
small  quantities  of  ammonia  being  also  evolved. 

After  having  rested  for  several  hours  the  fluid  is  subjected 
to  distillation.  In  Fig.  87,  a  represents  the  copper  still,  b  an 
ellipsoidal  or  egg-shaped  vessel  which  serves  as  a  receiver,  and 
c  the  rectifying  apparatus,  consisting  of  a  series  of  Pistorius's 
basins  into  the  uppermost  of  which  a  moderate  current  of 
water  is  conducted  ;  d  is  the  condenser. 

The  still  a  has  a  capacity  of  1000  to  1200  quarts  ;  the  steam 
pipe  placed  in  it  is  2  inches  in  diameter  and  32  feet  long. 
The  vapors  pass  out  through  the  wide  pipe  in  the  cover,  and 
what  is  condensed  in  b  runs  back  through  a  narrower  pipe 
into  a.  In  the  rectifying  vessel  or  rather  dephlegmator,  the  ris- 
ing vapors  are  forced  to  pass  around  a  copper  disk  placed  in 
each  basin,  and  thus  to  come  in  contact  with  the  surface  of 
the  basin  cooled  by  water.  From  this  it  is  evident  that  the 
less  volatile  bodies  are  condensed  in  the  basins  and  run  back 
into  b  and  from  there  into  a,  while  the  more  volatile  vapors 


350 


MANUFACTURE    OF    VINEGAR. 


pass  through  the  swan-neck  and  are  condensed  in  d.  Much, 
of  course,  depends  on  the  quantity  (and  temperature)  of  the 
water  running  into  the  rectifying  vessel. 

With  a  rectifying  vessel  consisting  of  seven  basins,  each 
1.64  feet  in  diameter,  and  with  a  correctly  conducted  inflow 
of  water,  a  product  of  0.816  specific  gravity  is  obtained  by  one 
operation  from  crude  wood  spirit  of  0.965  specific  gravity. 

This  product  can  be  used  for  many  purposes,  for  instance 
in  the  preparation  of  varnishes.  It  is,  however,  not  entirely 

FIG.  87. 


pure,  being  rendered  turbid  by  water  which  is  due  to  a  content 
of  the  previously  mentioned  hydrocarbons;  it  further  contains 
some  acetone,  methyl  acetate,  aldehyde,  ammonia,  methyl- 
amine,  and  is  not  lit  for  use  in  the  production  of  aniline 
colors. 

For  further  purification,  this  rectified  wood-spirit  is  diluted 
with  water  until  it  shows  a  specific  gravity  of  0.934,  and  is 
then  allowed  to  rest  a  few  days,  when  the  greater  portion  of 
the  hydrocarbons  lias  separated  as  an  oily  layer  on  the  top. 
The  clear  fluid  is  now  again  rectified  with  an  addition  of  2  to 


PREPARATION    OF    PURE    WOOD    SPIRIT.  351 

3  per  cent,  of  lime  whereby  a  distillate  is  obtained  which  does 
not  become  turbid  with  water,  but  in  time  turns  yellow. 

For  the  preparation  of  wood  spirit  suitable  for  denaturing 
purposes,  the  crude  wood  spirit  is  diluted  with  water  to  from 
30  to  40  per  cent.,  compounded  with  milk  of  lime — 20.30 
liters  to  every  1000  liters  of  spirit — and  carefully  and  slowly 
rectified  from  large  columnar  stills  for  several  days,  whereby 
the  following  fractions  are  obtained  : 

1.  First  runnings  containing  acetone,  with  60  to  80  per 
cent,  acetone.  2.  High  per  cent,  intermediate  runnings,  giv- 
ing bright  mixtures  with  water,  and  containing  7  to  10  per 
cent,  of  acetone.  3.  High  per  cent,  intermediate  running, 
not  giving  bright  mixtures  with  water.  4.  Allyl  alcohol-like 
after  runnings  below  90  percent.  5.  After  runnings  contain- 
ing oil. 

If  the  first  of  these  fractions  be  diluted  with  water — 100 
liters  of  water  to  200  kilogrammes  of  distillate — and  acidu- 
lated with  somewhat  more  sulphuric  acid  than  required  for 
fixing  the  bases  and  again  distilled  from  an  iron  or  copper 
still  lined  inside  with  lead,  a  product  suitable  for  denaturing 
purposes  is  obtained.  For  this  purpose  all  the  fractions  are 
used  which  are  miscible  with  water  without  becoming  turbid 
and  are  so  rich  in  acetone  that  the  mixture  finally  contains  at 
least  30  per  cent,  of  it  and  has  a  specific  gravity  of  90°  Tralles. 

For  the  further  treatment  of  fraction  2,  water  in  the  pro- 
portion of  1:2  is  also  added  and  then  1  to  3  per  cent,  of  soda 
lye.  The  object  of  the  addition  of  soda  lye  is  to  fix  the  phenol- 
like  body,  to  saponify  the  esters  and  resinify  the  aldehyde. 
During  rectification  the  fractions  that  possess  less  than  0.1  per 
cent,  acetone  are  caught  by  themselves  and  designated  "  pure 
methyl." 

The  third  fraction  is  treated  in  the  same  manner  but  in 
place  of  soda  lye,  sulphuric  acid  is  added.  The  fourth  frac- 
tion is  so  far  diluted  with  water  that  the  dissolved  oils  are 
separated.  The  latter  are  removed  and  the  residue,  after  add- 
ing sulphuric  acid,  is  again  rectified,  products  which  may  also 


352  MANUFACTURE  OF  VINEGAR. 

partially  serve  as  wood  spirit  for  denaturing  purposes  being 
thus  obtained. 

Preparation  of  Acetone. — Acetone  is  a  clear,  mobile,  ethereal- 
smelling  liquid,  boiling  at  134°  F.,  and  of  specific  gravity 
0.797  at  59°  F.  It  is  prepared  by  heating  calcium  acetate  in 
retorts  which  are  connected  with  a  cooling  apparatus.  The 
calcium  acetate  used  for  the  purpose  must  be  pure  and  should 
be  brought  into  the  retorts  in  a  perfectly  dry  and  pulverized 
state.  It  is  then  slowly  heated  until  no  more  fluid  runs  off 
from  the  cooler.  The  residue  in  the  retorts  consists  of  calcium 
carbonate,  and  is  again  used  for  the  preparation  of  calcium 
acetate.  Since  acetone  boils  at  a  very  low  temperature,  pro- 
vision must  be  made  for  abundant  cooling  and  it  is  best  to 
use  ice  water  for  feeding  the  cooling  apparatus. 

The  decomposition  of  the  calcium  acetate  to  acetone  and 
calcium  carbonate  proceeds  according  to  the  following  equation: 

(CH3.COO)2Ca  =  CaCO3  -f  2CH3.CO.CH3. 

This  decomposition  commences  already  in  a  slight  degree 
at  302°  F.,  but  takes  place  completely  only  at  752°  F.,  and 
hence  the  use  of  uniform  and  very  high  temperatures  is  indis- 
pensable for  the  production  of  acetone.  The  theoretical  yield 
from  200  Ibs.  of  calcium  acetate  (gray  acetate)  amounts  in 
round  numbers  to  66  Ibs.  of  acetone.  Since  the  gray  acetate 
contains  besides  calcium  acetate  other  combinations,  for  in- 
stance, calcium  butyrate  and  propionate,  the  yield  may  be 
materially  less,  and  may  in  round  numbers  be  given  as  about 
44  Ibs.  of  acetone  (dimethylketone).  The  homologues  men- 
tioned are  of  course  also  decomposed  in  a  manner  similar  to 
the  calcium  acetate,  but  higher  ketones  are  then  formed  which 
in  the  purification  of  the  crude  acetone,  yield  the  so-called 
acetone  oils. 

The  decomposition  of  the  calcium  acetate  is  as  a  rule  effected 
in  a  cast-iron  pan,  Fig.  88,  furnished  with  a  powerful  stirrer 
and  a  man-hole  for  charging  the  calcium  acetate.  The  tem- 
perature for  decomposition  should  not  exceed  752°  F.,  and  is 


PREPARATION    OF    PURE    WOOD    SPIRIT. 


353 


controlled  by  a  pyrometer.  The  vapors  evolved  pass  first 
through  a  dust-separator  and  then  through  a  pipe  into  a  con- 
denser, where  they  liquefy. 

The  crude  distillate  is  rectified.  This  first  distillate  is 
diluted  to  one-half  with  J  volume  of  water  and  again  recti- 
fied, whereby  a  product  with  90  per  cent,  acetone  is  obtained. 
The  last  distillation  is  effected  with  the  addition  of  potassium 
permanganate.  The  first  two  or  three  liters  of  distillate  are 


FIG. 


caught  by  themselves,  and  then  all  that  boils  between  122° 
and  136.4°  F. 

Fig.  89  shows  the  arrangement  of  a  plant  for  the  production 
of  acetone.  It  contains  several  decomposing  apparatuses  for 
the  production  of  crude  acetone.  The  pipes  conducting  the 
vapors  enter  first  a  common  collecting  pipe,  and  from  there 
are  conducted  to  the  condenser  which  terminates  in  the  col- 
lecting vessel  F,  the  quantity  of  fluid  in  it  being  indicated  by 
23 


354 


MANUFACTURE    OF    VINEGAR. 


the  float  H.  The  decomposing  apparatuses  are  separated  by  a 
wall  from  the  condenser  and  rectifier ;  the  fireplaces  are  out- 
side the  working  room.  The  decomposing  apparatus  is 
equipped  with  a  dust  collector  T,  above  which  is  a  broad 
T-pipe  for  conducting  the  vapors.  This  pipe  also  serves  for 
the  purpose  of  cleaning  the  dust  collector. 

From  the  collecting  vessel  the  crude  acetone  is  pumped  into 
the  rectifier  M,  the  latter  being  similar  in  arrangement  to  an 

FIG.  89. 


apparatus  for  rectifying  alcohol.  The  pure  acetone  is  caught 
by  itself  in  the  vessel  G. 

The  use  of  acetate  of  barium,  strontium  or  magnesium  in 
place  of  calcium  acetate  is  more  advantageous.  The  draw- 
back with  the  use  of  calcium  acetate  consists  in  that  man) 
tarry  substances  pass  over  and  clog  the  pipes,  and,  besides,  the 
distillate  is  contaminated  with  empyreumatic  substances. 

The  preparation  of  pure  acetone  is  not  very  easy,  notwith- 
standing its  apparent  simplicity,  and  requires  the  use  of  per- 
fectly separating  columnar  stills  and  experience,  for  the  rea- 
son that  the  admixtures  of  the  acetone  have  nearly  the  same 
boiling  points.  The  acetone  vapors  are  inflammable  and  when 
mixed  with  air  explosive. 


PREPARATION    OF    PURE    WOOD    SPIRIT.  355 

According  to  F.  H.  Meyer's  system,  German  patent  134,978, 
pure  acetone  is  manufactured  by  spreading  the  gray  acetate 
in  layers  2  to  4  centimeters  deep  upon  sheets  or  sieves,  which 
rest  upon  trucks  and  are  pushed  into  the  distilling  muffles. 
These  muffles  are  capable  of  working  up  4400  Ibs.  of  calcium 
acetate  in  24  hours.  They  are  heated  by  a  direct  fire,  a  uni- 
form distribution  of  the  heat  and  the  same  heating  at  all  points 
of  the  charge  being  secured  by  proper  regulation  of  the  fire. 
When  the  acetone  has  been  distilled  off  and  the  last  remnants 
blown  out  with  steam,  the  truck  is  removed  from  the  muffle 
and  is  replaced  by  another  previously  charged  with  calcium 
acetate. 

The  acetone  oils  which,  as  previously  mentioned,  are  ob- 
tained in  the  purification  of  crude  acetone  are  decomposed  to 
two  groups,  namely  to  white  acetone  oil  which  comprises  the 
fractions  boiling  at  from  167°  to  466°  F..  and  to  yellow  ace- 
tone oil  boiling  between  466'°  and  502°  F.  These  oils  are 
used  in  the  celluloid  industry  and  as  additions  to  wood  alco- 
hol intended  for  denaturing  purposes. 

Working  the  wood  tar. — Wood  tar  contains  a  large  quantity 
of  combinations  of  which,  however,  only  the  mixture  found 
in  commerce  under  the  name  of  creosote  can  be  separated  to 
advantage.  By  itself  wood  tar  may  be  utilized  as  a  preserva- 
tive coating  for  wood,  as  well  as  for  obtaining  soot,  and  event- 
ually as  fuel  in  the  destructive  distillation  of  wood. 

While  beech  tar,  for  instance,  contains  without  doubt  con- 
siderable paraffin,  it  cannot  be  produced  on  a  large  scale  at  a 
price  to  compete  with  that  of  the  product  obtained  from  crude 
petroleum.  The  tar  obtained  from  resinous  woods  contains 
oil  of  turpentine  and  can  be  worked  to  greater  advantage  than 
that  from  hard  wood. 

Preparation  of  creosote  and  tar  oils.  The  wood  tar  is  subjected 
to  distillation,  this  being  best  effected  in  a  horizontal  still  of 
the  shape  of  a  steam  boiler  and  so  bricked-in  as  to  be  slightly 
inclined  towards  one  side.  On  the  lowest  part  of  the  still  is  a 
larger  aperture  which  can  be  closed  by  a  cover  and  clamp. 


356  MANUFACTURE    OF    VINEGAR. 

The  object  of  this  arrangement  is  to  facilitate  the  quick  removal 
of  the  pitch-like  or  asphalt-like  mass  which  remains  behind  in 
the  still  after  the  volatile  products  have  been  distilled  off,  and 
which,  if  allowed  to  become  cold,  adheres  so  firmly  to  the 
sides  of  the  still  that  it  can  be  detached  only  with  great  diffi- 
culty. 

All  the  tarry  substances,  which  separate  in  distilling  wood- 
spirit  from  wood  vinegar,  and  in  neutralizing  with  lime  or 
soda,  are  combined  with  the  tar  taken  from  the  condensing 
vessels,  and  the  mass  thus  obtained  is  subjected  to  distillation. 
The  latter  might  be  conducted  so  that  the  distillates  resulting 
at  certain  temperatures  are  caught  by  themselves  and  the 
distillate  fractionated  ;  but,  as  a  rule,  the  distillates  are  only 
separated  in  such  a  manner  that  only  the  light  oleaginous 
products  up  to  specific  gravity  0.980  are  caught  by  themselves 
and  worked  further,  separately  from  the  heavy  oils  of  upward 
of  1.010  specific  gravity. 

At  the  commencement  of  distillation  crude  wood-spirit  first 
passes  over,  which  is  followed  by  quite  a  quantity  of  acetic  acid 
(distilled  wood-vinegar).  Next  the  light,  and  later  on  the 
heavy,  oils  pass  over,  a  pitch-like  residue  remaining  in  the  still. 
By  mixing  this  residue,  while  still  in  a  liquid  state,  with  dry 
hot  sand,  blocks  may  be  shaped  from  the  mass  thus  obtained, 
which  may  be  used  for  paving,  like  asphalt  blocks.  Mixed 
with  culm  it  yields  a  dough-like  mass  which  may  be  utilized 
for  the  manufacture  of  briquettes.  If  the  residue  cannot  be 
utilized  in  any  other  manner,  it  may  be  allowed  to  run  upon 
iron  plates,  and  when  cold,  is  broken  up  into  small  pieces  and 
used  as  fuel  together  with  coal. 

The  quantities  of  the  separate  products  of  distillation  depend 
on  the  nature  of  the  wood  from  which  the  tar  has  been  ob- 
tained and  on  the  manner  in  which  destructive  distillation  has 
been  conducted.  Hard  woods  give  on  an  average  a  tar  which 
by  distillation  yields,  according  to  Vincent : 


PREPARATION    OF    PURE    WOOD    SPIRIT.  357 

Watery  distillate  (wood  spirit,  acetic  acid)  .    .    .  10  to  20  per  cent. 
Oleaginous  light  distillate,  sp.  gr.  0.966  to  0.977  .  10  to  15       " 
"         heavy      "              "      1.014  to  1.021  .  15       " 

Pitch 50  to  62      " 

The  distillates,  according  to  their  specific  gravities,  are  caught 
separately  in  vats,  a  sample,  for  instance,  1  quart  of  the  fresh 
distillate,  being  immediately  taken  for  the  purpose  of  accurately 
determining  the  quantity  of  soda  required  for  neutralizing  the 
total  quantity  of  fluid.  The  quantity  of  concentrated  soda 
solution  necessary  for  neutralization  is  then  added  to  the  dis- 
tillate, the  whole  thoroughly  mixed,  and  the  fluid  allowed  to 
repose  until  two  sharply  separated  layers  are  formed,  the  upper 
one  of  which  is  of  an  oleaginous  nature.  The  watery  fluid  is 
then  allowed  to  run  off  and  is  brought  into  one  of  the  vats  in 
which  crude  wood-vinegar  is  caught.  The  oleaginous  layer  is 
worked  further  by  distillation. 

The  oils  remaining  after  neutralizing  the  light  and  heavy 
distillates  are  combined  and  subjected  to  careful  rectification. 
The  receiver  is  changed  as  soon  as  it  is  ascertained  by  the 
thermometer  that  the  temperature  has  risen  above  302°  F., 
and  is  again  changed  when  the  temperature  rises  above  482° 
F.  The  hydrocarbons  distilling  over  at  below  302°  and  above 
482°  F.  might  be  used  as  solvents  and  for  illuminating  pur- 
poses, but  their  preparation  is  not  remunerative. 

The  distillate  which  has  passed  over  between  302°  F.  and 
482°  F.  contains  phenol,  cresol  and  phlorol,  which  together 
form  wood-creosote.  The  distillate  is  intimately  mixed  with 
the  assistance  of  a  stirring  apparatus  with  highly  concentrated 
soda  lye  (36°  Be.),  and  the  watery  fluid  is  drawn  off  from  the 
supernatant  layer  of  oil,  which  is  combined  with,  the  other 
hydrocarbons.  The  watery  fluid  is  for  some  time  boiled  in  an 
open  pan  to  expel  any  hydrocarbons  still  present,  and  is  then 
saturated  with  sulphuric  acid  and  allowed  to  repose.  The 
fluid  of  a  penetrating  odor  separated  thereby  is  creosote,  which 
is  used  for  medicinal  purposes.  As  a  disinfecting  agent  it  has, 
however,  been  superseded  by  the  cheaper  coal-tar  creosote 
(carbolic  acid). 


358  MANUFACTURE    OF    VINEGAR. 

To  obtain  the  creosote  prepared  according  to  this  process 
permanently  colorless,  it  is  mixed  with  J  to  J  per  cent,  of 
potassium  dichromate  and  £  to  1  per  cent,  of  sulphuric  acid, 
allowed  to  repose  for  24  hours  and  again  distilled.  The  small 
yield  of  creosote  and  its  limited  use  make  its  profitable  manu- 
facture rather  doubtful,  except  where  sulphuric  acid  and  soda 
can  be  procured  at  cheap  rates. 

The  heavy  oils  are  worked  up  in  the  same  manner.  The 
solution  formed  after  treatment  with  soda  solution  is  not  added 
to  the  crude  wood-vinegar,  but  treated  by  itself,  as  it  contains 
scarcely  any  sodium  acetate,  but  the  sodium  salts  of  the  fatty 
acids  with  higher  boiling  points,  such  as  propionic,  butyric, 
valeric  and  caproic  acids.  This  lye  is  used  either  for  the 
preparation  of  these  acids,  or  the  solution  is  evaporated  to 
dryness  and  ignited  with  the  admittance  of  air  to  regain  the 
soda. 

If  the  acids  are  to  be  prepared,  the  solution  is  evaporated 
to  the  consistency  of  syrup,  slightly  oversaturated  with  sul- 
phuric acid,  and  the  resulting  fluid  diluted  with  water.  The 
oleaginous  layer  collecting  upon  the  surface  consists  of  a  mix- 
ture of  the  above-mentioned  acids  which  are  soluble  with  diffi- 
culty in  water.  By  rectifying  the  mixture  at  the  temperatures 
corresponding  to  the  boiling  points  of  the  various  acids,  the 
latter  are  obtained  in  an  almost  pure  state. 

It  is  still  more  suitable  to  distil  the  mass  previously  evapo- 
rated to  the  consistency  of  syrup  with  alcohol  and  sulphuric 
acid,  whereby  the  odoriferous  ethers  of  the  various  acids  are 
formed,  which  can  then  be  separated  by  fractional  distillation. 

Since  the  heavy  tar  oils  are  entirely  free  from  acid,  and  do 
not  gurn  in  the  air,  they  may  be  used  as  lubricants  for  ma- 
chinery, and  were  formerly  much  sought  after  for  that  pur- 
pose ;  but  at  present  they  have  been  largely  superseded  by 
petroleum  products,  and  in  consequence  of  this  are  of  less 
value. 

In  the  northern  parts  of  Sweden  and  Finland  considerable 
quantities  of  birch-tar  oil  are  prepared,  and  below  are  given 


PREPARATION    OF    PURE    WOOD    SPIRIT.  359 

* 

the  results  of  a  series  of  experiments  regarding  the  products 
which  were  obtained  in  the  distillation  of  a  sample  of  Finland 
birch-tar  oil. 

No.  of  the  distillate.  Limits  of  boiling  points.  Specific  gravity. 

1 212°  to  226°  F.  0.887 

2.    .    .    ....    4,...    .    -       .    .    356°  to  437°  F.  1.020 

3 .   .  ,    588°  to  644°  F. 

No.  1  formed  a  red-yellow,  very  mobile  oil  of  a  not  dis- 
agreeable odor  of  birch  tar.  No.  2  was  of  a  darker  color  and 
of  a  less  agreeable  odor,  while  No.  3  represented  a  dark  brown, 
very  viscous  mass.  By  heating  the  residue  in  the  still  to 
above  644°  F.,  it  is  suddenly  decomposed,  heavy  vapors  being 
evolved  and  a  lustrous,  very  porous  coal  remaining  behind. 

By  distilling  the  tar  oil  with  caustic  soda  quite  a  series  of 
oleaginous  distillates  are  obtained.: 

No.  of  the  distillate.  Limits  of  boiling  points.  Specific  gravity. 

1 212°  to  284°  F.  1.046 

2 ;..-.-.  .    .   .    284°  to  392°  F.  1.114 

3 i.    .   ........    .    392°to437°F.  1.171 

4 -'.  ' , '  ,    .    437°  to  482°  F.  1.058 

5 ':..:'.   .  .    .,  .    .    482°  to  734°  F.  1.039 

Nos.  1  to  3  were  pale,  red-yellow  oils ;  Nos.  4  and  5  darker 
and  more  viscous.  The  residue  remaining  in  the  still  at  above 
734°  F.  was  a  dark  black  mass,  soft  and  flexible  at  the  or- 
dinary temperature,  and  becoming  hard  only  at  a  lower  tem- 
perature. 


PART  II. 

MANUFACTURE  OF  CIDERS,  FRUIT-WINES,  ETC. 


CHAPTER  XXVII. 

INTRODUCTION. 

THE  term  wine  in  general  is  applied  to  alcoholic  fluids 
which  are  formed  by  the  fermentation  of  fruit  juices,  and 
serve  as  beverages.  According  to  this  definition,  there  may 
actually  be  as  many  kinds  of  wine  as  there  are  fruits  whose 
juices,  in  consequence  of  their  content  of  sugar,  are  capable 
of  vinous  fermentation  ;  and,  in  fact,  besides  the  apple  and 
pear,  there  are  many  other  fruits  which  are  likewise  applicable 
to  wine-making.  Among  these  may  be  named,  currants, 
gooseberries,  mulberries,  elderberries,  cherries,  oranges,  dates, 
pine-apples,  raspberries,  strawberries,  etc.  But,  in  order  to 
make  the  product  from  such  fruits  resemble  the  standard  wine 
made  from  grapes,  various  ingredients  have  to  be  added,  as, 
for  instance,  an  acid,  spices,  coloring,  and  an  astringent,  to 
replace  the  extractive  matter.  Tartaric  acid  is,  as  a  rule, 
used  as  an  acid  addition,  and  elderberry  or  whortleberry  juice 
as  coloring  matter.  The  "water  employed  in  the  manufacture 
should  be  pure  and  soft. 

Ripening  of  fruits, — In  order  to  form  a  clear  idea  of  the 
process  which  takes  place  during  the  growth,  ripening,  and 
final  decomposition  of  a  fruit,  it  is  necessary  to  refer  to  the 
constituents  which  are  found  in  an  unripe  fruit  at  its  first 
appearance. 

(360) 


INTRODUCTION.      -  361 

Besides  water,  the  quantity  of  which  varies  between  90  and 
45  per  cent.,  fruits  contain  partly  soluble  and  partly  insoluble 
substances.  The  juice  obtained  by  pressure  contains  the  sol- 
uble constituents,  such  as  sugar,  gum,  tannin,  acids,  salts,  etc., 
while  the  remaining  insoluble  portion  consists  chiefly  of  cellu- 
lose, starch,  a  gum-like  body,  a  few  inorganic  substances,  and 
further,  the  characteristic  constituent  of  unripe  fruits,  to  which 
the  term  pectose  has  been  applied.  It  forms  the  initial  point 
for  the  phenomena  observed  during  the  growth  and  ripen- 
ing of  fruits,  and,  therefore,  requires  a  somewhat  closer  ex- 
amination. 

In  regard  to  its  behavior,  pectose  approaches  cellulose  and 
starch.  It  is  chiefly  found  in  the  pulp  of  unripe  fruits,  but 
also  in  certain  roots,  especially  in  carrots,  beets,  and  others. 
It  is  insoluble  in  water,  spirits  of  wine,  and  ether,  but  during 
the  ripening  of  the  fruit  it  undergoes  a  change,  induced  by  the 
acids  and  heat,  and  is  converted  into  pectine,  which  is  readily 
soluble  in  water.  To  pectose  are  due  the  hardness  of  unripe 
fruits  and  also  the  property  of  many  fruits  and  roots  of  boil- 
ing hard  in  water  containing  lime,  the  pectose  combining  with 
the  lime. 

The  formation  of  pectine  commences  as  soon  as  the  fruits 
are  exposed  to  the  action  of  heat,  and  then  depends  on  the  in- 
fluence of  the  vegetable  acid  present  upon  the  pectose.  This 
can  be  shown  by  expressing  the  pulp  of  an  unripe  apple.  The 
juice  thus  obtained  contains  scarcely  a  trace  of  pectine,  but, 
by  boiling  it  for  a  few  minutes  with  the  pulp  of  the  fruit,  the 
fluid,  in  consequence  of  the  formation  of  pectine,  acquires  a 
viscous  quality,  like  the  juice  obtained  from  ripe  fruits. 

Pectine,  nearly  pure,  is  white,  soluble  in  water,  non-crystal- 
lizable,  and  without  effect  upon  vegetable  colors.  From  its 
dilute  solution  it  is  by  alcohol  separated  as  a  jelly,  and  from 
its  more  concentrated  solution,  in  long  threads.  Brought  into 
contact  with  alkalies  or  alkaline  earths,  pectine  is  transformed 
into  pectic  acid.  Under  the  influence  of  a  peculiar  ferment 
called  pectase,  which  will  be  described  later  on,  pectine  is 


362  MANUFACTURE    OF    VINEGAR. 

transformed  into  pectosic  acid,  and  by  dilute  acids  into  meta- 
pectic  acid. 

By  boiling  a  solution  of  pectine  in  water  for  a  few  hours,  it 
partially  loses  its  viscous  condition  and  separates  a  substance 
called  parapectine,  which  shows  the  same  behavior  as  pectine, 
except  that  it  is  not  precipitated  by  neutral  lead  acetate. 
When  treated  with  dilute  acids  the  parapectine  is  transformed 
into  metapectine,  which  might  be  called  metapectous  acid,  as 
it  shows  a  decidedly  acid  reaction  and  colors  litmus  paper 
strongly  red. 

Metapectine  is  soluble  in  water,  non-crystallizable,  and,  like 
pectine  and  parapectine,  insoluble  in  alcohol,  which  precipi- 
tates it  from  its  solutions  in  the  form  of  a  jelly.  On  being 
brought  into  contact  with  bases  it  is  also  transformed  into 
pectic  acid.  It  differs  from  pectine  and  parapectine  in  that 
the  solution  is  precipitated  by  barium  chloride. 

Pectase,  the  peculiar  ferment  previously  referred  to,  is  sim- 
ilar in  its  mode  of  action  to  diastase  and  emulsion.  It  can  be 
obtained  by  precipitating  the  juice  of  young  carrots  with  alco- 
hol, whereby  the  pectose,  which  was  at  first  soluble  in  water, 
becomes  insoluble,  without,  however,  losing  its  effect  upon  the 
pectous  substances. 

By  adding  pectase  to  a  solution  of  pectine,  the  latter  is  im- 
mediately converted  into  a  jelly-like  body,  insoluble  in  water. 
This  phenomenon  is  the  pectous  fermentation,  which  may  be 
compared  with  lactic  acid  fermentation.  It  is  not  accom- 
panied by  an  evolution  of  gas,  and  may  take  place  with  the 
air  excluded,  a  temperature  of  86°  F.  being  most  favorable  for 
its  progress. 

Pectase  is  an  amorphous  substance.  By  allowing  it  to  stand 
in  contact  with  water  tor  a  few  days,  it  decomposes,  becomes 
covered  with  mold-formations,  and  loses  its  action  as  a  fer- 
ment, this  action  being  also  destroyed  by  continued  boiling. 
In  the  vegetable  organism  it  occurs  in  a  soluble  as  well  as  in- 
soluble state. 

Roots  such  as  carrots,  beets,  etc.,  contain  soluble  pectase 


INTRODUCTION.  363 

and  their  juice  added  to  a  fluid  containing  pectine  in  solution 
immediately  induces  pectous  fermentation,  while  the  juice  of 
apples  and  other  acid  fruits  produces  no  effect  upon  pectine, 
the  latter  being  present  in  them  in  a  modified  insoluble  form 
and  accompanying  the  insoluble  portion  of  the  pulp.  On 
adding  the  pulp  of  unripe  apples  to  a  pectine  solution  it  gel- 
atinizes in  a  short  time,  in  consequence  of  the  formation  of 
pectosic  and  pectic  acids.  It  is  therefore  due  to  the  presence 
of  these  acids  that  many  ripe  fruits  are  so  easily  converted 
into  jellies. 

Pectosic  acid  is  the  result  of  the  first  effect  of  the  pectase 
upon  pectine  ;  it  being,  however,  also  formed  by  bringing 
dilute  solutions  of  potash,  soda,  ammonia  or  alkaline  carbon- 
ates in  contact  with  pectine.  In  all  these  cases  salts  are  formed 
which,  when  treated  with  acids,  yield  pectosic  acid.  The  lat- 
ter is  gelatinous,  and  with  difficulty  dissolves  in  water.  In 
the  presence  of  acids  it  is  entirely  insoluble.  It  is  quickly 
transformed  into  pectic  acid  by  long  boiling  in  water,  by  pec- 
tase, or  by  an  excess  of  alcohol. 

By  allowing  pectase  to  act  for  some  time  upon  pectine,  pec- 
tic acid  is  formed  ;  the  same  conversion  taking  place  almost 
instantaneously  by  dilute  solution  of  potash,  soda,  ammonia, 
alkaline  carbonates,  as  well  as  by  barium,  lime  and  strontium 
water.  Its  formation  in  the  above-described  manner  is  pre- 
ceded by  that  of  pectosic  acid,  which,  as  previously  men- 
tioned, is  converted  by  the  same  agents  into  pectic  acid. 

Pectic  acid  is  insoluble  in  cold,  and  scarcely  soluble  in  hot, 
water.  By  boiling  it,  however,  for  a  certain  time  in  water,  and 
constantly  replacing  the  water  lost  by  evaporation,  it  disappears 
entirely,  and  is  converted  into  a  new  acid,  soluble  in  water. 
Alkalies  decompose  it  very  rapidly,  the  final  result  being  met- 
apectic  acid,  which  is  soluble  in  water,  but  non-crystallizable. 
On  boiling  in  hot  water,  the  solution  forms,  after  cooling,  a 


Pectic  acid  further  possesses  the  special  property  of  dissolv- 
ing in  a  large  number  of  alkaline  salts  and  forming  with  them 


364  MANUFACTURE    OF    VINEGAR. 

true  double  salts,  which  always  show  a  decidedly  acid  reaction, 
dissolve  in  water,  and  on  cooling  form  consistent  jellies. 

By  boiling  for  a  few  hours  a  solution  of  a  pectous  salt,  the 
latter  is  transformed  into  a  parapectous  salt  which,  when  de- 
composed by  a  dilute  acid,  yields  parapectic  acid.  It  is  non- 
crystallizable,  shows  a  strong  acid  reaction,  and  forms  with 
alkalies  soluble  salts.  It  is  precipitated  by  barium  water  in 
excess, 

Metapectic  acid  is  formed  in  various  ways,  among  others 
by  leaving  an  aqueous  solution  of  parapectic  acid  to  itself  for 
some  time,  but  also  by  the  action  of  the  lime  contained  in  the 
cell-tissues  of  roots  and  fruits  upon  pectose.  It  is  insoluble  in 
water,  does  not  crystallize,  and  gives  soluble  salts  with  all 
bases.  With  an  excess  of  bases  the  salts  acquire  a  yellow 
coloration.  They  are  precipitated  by  basic  lead  acetate. 

What  has  been  said  in  the  preceding  may  be  briefly  con- 
densed as  follows : — 

1.  By  the  influence  of  heat  upon  pectose  pectine  is  formed. 

2.  Pectine  is  transformed   into  parapectine  by  boiling  its 
aqueous  solution  for  several  hours. 

3.  Parapectine,  when  treated  at  a  boiling  heat  with  dilute 
acids,  is  converted  into  metapectine. 

4.  Pectase  converts  pectine  into  pectic  acid. 

5.  By  long-continued  action  of  pectase  upon  pectine,  pectic 
acid  is  formed. 

6.  Pectic  acid  is  by  boiling  water  transformed   into  para- 
pectic acid. 

7.  An  aqueous  solution  of  parapectic  acid  is  rapidly  con- 
verted into  metapectic  acid. 

All  these  bodies  are  derived  from  pectose,  which  through  all 
these  transformations  has  not  even  suffered  a  change  in  the 
proportion  of  weight  of  its  constituents  (carbon,  hydrogen,  and 
oxygen);  and  hence  all  have  the  same  qualitative  and  quanti- 
tative compositions.  This  may,  perhaps,  sound  odd,  but 
chemistry  presents  numerous  analogies  for  such  cases,  and 
hence  the  term  isomeric  has  been  applied  to  bodies  which,  with 


INTRODUCTION.  365 

the  same  quantitative  composition,  exhibit  very  different 
chemical  properties. 

The  changes  pectose  undergoes  by  the  influence  of  heat,  by 
the  action  a  peculiar  ferment,  acid  and  alkalies,  and  the  re- 
sulting combinations  mentioned  above,  have  of  course  been 
artificially  effected  by  chemical  means.  They  resemble,  how- 
ever, so  closely  the  state  of  fruits  in  the  course  of  their  growth 
and  ripening,  and  the  influences  and  conditions  to  which  fruits 
are  exposed  in  nature  are  sufficiently  similar  to  those  artifi- 
cially induced,  that  their  action  may  be  reasonably  supposed  to 
be  the  same.  We  know  from  daily  experience  that  heat  pro- 
motes the  development  and  ripening  of  fruit.  Fruits  contain 
pectose  and  acids,  and  alkalies  and  bases  are  conducted  to 
them  from  the  soil ;  and  hence  in  fruit  in  a  normal  state  of 
development  none  of  the  chemical  agents  are  wanting  which 
the  chemist  uses  for  the  production  of  derivatives  of  pectose. 

If  the  transformation  of  substances  under  the  influence  of 
other  substances  be  considered  as  dependent  on  chemical 
processes,  the  development  of  a  fruit  from  its  first  formation 
to  complete  ripeness,  and  even  to  its  decomposition,  rotting, 
and  putrefaction,  is  a  chemical  process  in  the  widest  sense  of 
the  word.  This  is  evident,  not  only  from  what  has  been  said 
in  the  preceding,  but  has  also  been  plainly  shown  by  special 
chemical  researches  into  the  changes  fruits  undergo  during 
their  development  and  perfection.  The  results  of  these 
researches  are  briefly  as  follows  : — 

1.  The  quantity  of  water  contained  in  the  pulp  of  a  fruit 
is  considerable ;  it  varying  between  45  and  90  per  cent.     In 
many  fruits  the  content  of  water  remains  unchanged  during 
the  different  periods  of  ripening,  but,  as  a  rule,  it  is  somewhat 
greater  in  the  commencement. 

2.  Fruits  of  the  same  kind  examined  at  the  same  season  of 
the  year  always  contain  the  same  quantity  of  water  ;  the  same 
holding  good  as  regards  the  various  parts  of  the  pulp  of  a  fruit. 

3.  The  solid  constituents  in  the  pulp  of  fruits  amount  to 
between  10  and  25  per  cent.     They  consist  of  soluble  substances 


366  MANUFACTURE    OF    VINEGAR. 

which  dissolved  in  the  water  from  the  juice  of  the  fruits  ;  and 
of  insoluble  bodies  which  compose  the  membranes  of  the  cells. 

4.  The  quantity  of  soluble  substances  always  increases  with 
increasing  ripeness,  while  the  weight  of  the  insoluble  decreases  ; 
and  hence  it  may  be  said  that  the  soluble  substances  contained 
in  the  juice  of  a  fruit  are  formed  at  the  expense  of  the  insolu- 
ble portion  of  the  pulp.     The  bodies  which  become  soluble 
are  starch,  pectose,  and  a  gum-like  substance  capable  of  being 
converted  into  gum. 

On  this  modification  of  the  solid  portion  of  the  pulp  of  a 
fruit  depend  also  the  changes  a  fruit  undergoes  in  regard  to 
hardness  and  transparency  during  ripening. 

According  to  the  mode  of  action  of  the  pectase  and  acids 
upon  the  pectose,  all  ripe  fruits  contain  pectine. 

5.  Various  acid  fruits,  such  as  plums,  cherries,  etc.,  are  fre- 
quently observed  to  secrete  a  neutral  juice  which,  in  conse- 
quence of  the  evaporation  of  the  water,  leaves  a  gum-like 
substance  upon  the  exterior  of  the  fruit.     This  phenomenon 
throws  some  light  upon  the  separation  of  gum  as  it  appears  in 
many  trees,  and  which,  when  it  occurs  very  abundantly,  is 
actually  a  disease. 

In  fruits  becoming  thus  covered  with  a  gum,  a  transparent, 
neutral  substance  insoluble  in  water  occurs  stored  in  the  cells 
of  the  pulp.  Under  the  influence  of  nitrogenous  substances, 
which  act  as  a  ferment,  and  perhaps  also  of  acids,  this  gum-like 
substance  is  modified  and  transformed  into  actual  gum,  which 
is  then  converted  into  sugar  in  the  interior  of  the  pulp  of  the 
fruit ;  an  excess  of  this  gum-like  substance  being  secreted  and 
forming  a  firm  coating  upon  the  exterior  of  the  fruit. 

6.  The  sugar  occurring  in  ripe  fruits  is  evidently  derived 
from  various  sources.     The  occurrence  of  a  large  quantity  of 
starch  in  many  unripe  fruits,  especially  in  apples,  and  its  com- 
plete disappearance  at  the  time  of  ripeness,  allow  of  no  other 
explanation  than  that  the  sugar  occurring  in  fruits  is  formed 
by  the  conversion  of  the  starch  under  the  influence  of  the  acids 
present ;  other  indifferent  substances,  such  as  gum,  vegetable 


INTRODUCTION.  367 

mucus,  etc.,  undergoing  similar  transformations  and  yielding 
in  this  manner  a  certain  portion  of  sugar.  Even  tannin,  which 
occurs  in  all  unripe,  but  not  in  ripe,  fruits,  can  be  changed  by 
acids  and  ferments  so  as  to  form  sugar. 

Thus  far  nothing  justifies  the  supposition  that  the  acids  in 
fruits,  such  as  tartaric,  citric,  malic  acids,  are  converted  into 
fruit  sugar.  To  entertain  such  an  opinion  it  would  have  to 
be  supposed  that  the  molecules  of  these  acids,  which  are  far 
more  simple  than  those  of  fruit-sugar,  become  more  complex 
and  are  converted  into  sugar.  In  such  natural  transforma- 
tions the  reverse  is,  however,  generally  the  case,  the  molecules 
always  endeavoring  to  become  the  more  simple  the  farther  they 
withdraw  from  organized  structures. 

7.  It  has  been  attempted  to  explain  in  various  ways  the  very 
remarkable  phenomenon  of  the  gradual  disappearance  of  the 
acid  in  ripening  fruits.  It  might  not  be  impossible  that  the 
acid  of  a  fruit,  is  neutralized  by  the  bases  conducted  to  it 
through  the  juice  ;  or  that  it  is  covered  by  the  sugar  or  the 
mucous  substances  formed  in  the  juice  ;  or,  finally,  that  it  dis- 
appears at  the  moment  of  ripeness  by  suffering  actual  combus- 
tion. An  examination  of  these  various  theories  leads  to  the 
conclusion  that  the  acid  is  neither  neutralized  nor  covered  by 
the  sugar  or  the  mucous  substances,  but  that  it  actually  under- 
goes slow  combustion. 

During  the  stages  of  development  and  ripening,  a  fruit 
passes  through  two  different  stages  sharply  separated  from 
each  other  by  definite  chemical  phenomena.  In  the  first 
stage,  which  may  be  designated  as  that  of  growth,  whilst  the 
fruit  remains  green,  its  relation  to  the  atmosphere  appears  the 
same  as  that  of  leaves,  for  it  absorbs  carbonic  acid  and  evolves 
oxygen.  During  this  epoch  it  increases  rapidly  in  size,  and 
receives  through  the  stem  the  inorganic  substances,  indispens- 
able for  its  development,  and  the  water.  If,  at  this  stage,  it 
is  taken  from  the  tree,  it  soon  commences  to  wither  and  decay. 
But  in  the  second  period,  when  it  fairly  begins  to  ripen,  its 
green  color  is,  as  a  rule,  replaced  by  a  yellow,  brown-red,  or 


368  MANUFACTURE    OF    VINEGAR. 

red.  Oxygen  is  now  absorbed  from  the  air  and  carbonic  acid 
is  evolved,  whilst  the  starch  and  cellulose  are  converted  into 
sugar  under  the  influence  of  the  vegetable  acids,  and  the  fruit 
becomes  sweet.  When  the  sugar  has  reached  the  maximum 
the  ripening  is  completed,  and  if  the  fruit  be  kept  longer,  the 
oxidation  takes  the  form  of  ordinary  decay. 


CHAPTER  XXVIII. 

FRUITS    AND    THEIR    COMPOSITION. 

FOR  the  preparation  of  fruit-wines,  not  only  the  fruits  culti- 
vated in  our  gardens  and  orchards  on  account  of  their  fine 
flavor  are  used,  but  sometimes  also  others  which  do  not  by  any 
means  possess  an  agreeable  taste,  and  whose  juices,  after  fer- 
mentation, yield  a  product  which  has  at  least  only  a  very 
doubtful  claim  to  the  name  of  "  wine."  The  utilization  of  such 
material  for  wine-making  can  only  be  explained  by  special 
fancy,  and  hence  here  only  such  fruits  will  be  considered 
as,  on  account  of  the  nature  of  their  juices,  will  yield  with 
rational  treatment  a  beverage  of  a  sufficiently  agreeable  taste 
to  be  liked. 

For  making  fruit-wine,  sugar  not  only  by  itself  but  also 
in  its  proportion  to  the  free  acid  present,  is  undoubtedly  the 
most  important  constituent  of  the  fruit.  The  following  table 
from  Fresenius  gives  the  average  percentage  of  sugar  in 
different  varieties  of  fruit : 

I, 


Peaches 1.57  p.  c. 

Apricots.    .    .' 1.80 

Plums 2.12 

Keine  Claudes 3.12 

Greengages       ......  3.58 

Raspberries 4.00 

Blackberries 4.44 

Strawberries .5.73 

Whortleberries.  .    .5.78 


Currants 6. 10  p.  c. 

German  prunes 6.25  " 

Gooseberries 7.15  " 

Pears 7.45  " 

Apples 8.37  " 

Sour  cherries  ......    8.77  " 

Mulberries 9.19  " 

Sweet  cherries 10.79  '* 

Grapes 14.93  " 


FRUITS    AND    THEIR    COMPOSITION. 


369 


II.  Table   according   to   average   percentage  of  free   acid 
expressed  in  malic  acid  : 


Pears 0.07  p.  c. 

Greengages 0.58  u 

Sweet  cherries 0.62  " 

Peaches 0.67  " 

Grapes 0.74  " 

Apples 0.75  " 

German  prunes 0.89  " 

Keine  Claudes 0.91  " 

Apricots 1.09  " 


Blackberries 1.19  p.  c. 

Sour  cherries 1.28  " 

Plums 1.30  " 

Whortleberries 1.34  " 

Strawberries 1.37  " 

Gooseberries 1.45  " 

Kaspberries  .......  1.48  " 

Mulberries 1.86  " 

Currants.                                    .  2.04  " 


III.  Table  according  to  the  proportion  between  acid,  sugar, 
pectine,  gum,  etc. 


Plums 

Apricots  .... 
Peaches  .... 
Easpberries  .  . 
Currants.  .  .  . 
Keine  Claudes  . 
Blackberries  .  . 
Whortleberries  . 
Strawberries  .  . 
Gooseberries  .  . 
Mulberries  .  .  . 
Greengages  .  . 
Sour  cherries  .  . 
German  prunes  . 
Sweet  cherries  . 
Grapes  .... 
Pears  . 


Acid. 
1 
1 
1 
1 
1 
1 
1 
1 
1 
1 
1 
1 
1 
1 
1 
1 
1 


Sugar. 
1.63 
1.65 
2.34 
2.70 
3.00 
3.43 
3.73 
4.31 
4.37 
4.93 
4.94 
6.20 
6.85 
7.03 
11.16 
20.18 
94.60 


Pectine,  gum,  etc. 

3.14 

6.35 
11.94 

0.96 

0.07 
11.83 

1.21 

0.41 

0.08 

0.76 

1.10 

9.92 

1.43 

4.35 

5.60 

2.03 
44.40 


IV.  Table  according  to  the  proportion  between  water,  solu- 
ble and  insoluble  substances. 
24 


370 


MANUFACTURE    OF    VINEGAR. 


Composition  of  the  juice  in 
100  parts,  without  the  in- 
soluble substances; 

Water. 

Soluble 
substances, 

Insoluble 
substances.       Water. 

Soluble 
substances. 

Raspberries    .... 

100 

9.12 

6.88 

91.64 

8.3C 

Blackberries  .... 

100 

9.26 

6.46 

91.53 

8.47 

Strawberries  .... 
Plums     

100 
100 
100 

3.39 
9.94 
11.00 

5.15 
0.87 
6.62 

91.42 
91.13 
90.09 

8.58 
8.87 
9.91 

Currants     .    .    .    .    • 

Whortleberries.    .    . 

100 

12.05 

16.91 

89.25 

10.75 

Gooseberries  .... 

100 

12.18 

3.57 

89.14 

10.86 

Greengages     .... 
Auricots 

100 
100 
100 

13.04 
13.31 
14.25 

1.53 
2.07 
5.54 

88.46 
88.25 
87.52 

11.54 
11.75 

12.48 

Pears  

Peaches  

100 

14.64 

2.10 

87.23 

12.77 

German  prunes.     .    . 

100 

15.32 

3.15 

86.71 

13.29 

Sour  cherries     .    .    . 

100 

16.48 

•    1.31 

85.85 

14.15 

Mulberries     .... 

100 

16.57 

1.47 

85.79 

14.21 

Apples    

100 

16.89 

3.61 

85.46 

14.54 

Reine  Claudes      .    . 

100 

18.52 

1.22 

84.37 

15.63 

Sweet  cherries  .    .    . 
Graoes     .    .    . 

100 
100 

18.61 

2281 

1.53 

5.81 

84.30 
81.42 

15.70 

18.58 

V.  Composition 
sugar,  pectine,  etc. 


of  the  juice  according 
in  100  parts  : 


to  the  content  of 


Peaches  

Pectine, 
Sugar,       etc., 
p.  c.         p.  c. 
.  1.99       10.05 
2  04        6  98 

German  prunes  .... 

Pectine, 
Sugar,        etc., 
p.  c.          p.  c. 
7.56         4.70 
8.00         1.24 
8.12        0.77 
8.43        4.02 
9.14        4.59 
10.00        2.22 
10.44        2.17 
15.30        2.43 
16.15        2.07 

.     .        1.42  n.  r 

Apricots  . 
Plums 

.  2.13        8.19 
2.80        5.40 
.  4.18        6.45 
.  4.84        1.73 
.  5.32        1.72 
.  6.89        0.13 
.  7.30        0.16 

free  acid  in  1 

.    .    .  0.09  p.  c. 
.    .    .  0.59     " 
.    .    .  0.67     " 
.    .    .  0.80    u 
.  0  82     " 

Whortleberries   .    .    .    . 
Pears  

Apples  
^Mulberries  

Raspberries  
Blackberries  
Strawberries  
Currants  

VI.  Content  of 

Pears  
Reine  Claudes  .... 
Greengages  
Grapes  
Apples  

Sour  cherries  .        .    . 

Sweet  cherries.    .... 
Grapes  

.00  parts  of  juice  : 

Blackberries  .        ... 

Sour  cherries            .    . 

52      " 

57     " 

Gooseberries      .... 

1.63     u 

Plums  

.72     " 

Pparhptj 

0  85     u 

80    tk 

Sweet  cherries  .... 
German  prunes.  .  .  . 
Apricots. 

.    .      0.88     " 
.    .    .  1.08     " 
.  1.29     " 

.88     " 
2.02     " 
2.43     " 

Mulberries  
Currants  

FRUITS    AND    THEIR    COMPOSITION.  371 

Tables  V.  and  VI.  represent  the  proportion  in  which  the 
soluble  constituents  of  the  fruit  are  found  in  the  juice  or  must 
obtained  from  them.  In  the  practical  execution  of  the  pre- 
paration of  fruit  wines  we  will  have  occasion  to  refer  to  these 
tables. 

For  the  preparation  of  wine,  only  the  soluble  substances, 
which  pass  into  the  must,  and  from  which  the  wine  is  formed, 
are  chiefly  of  interest,  and  it  will  be  necessary  to  consider 
them  somewhat  more  closely. 

Grape-sugar  or  Glucose. — This  sugar  is  widely  diffused 
throughout  the  vegetable  kingdom,  it  occurring  in  most  kinds 
of  sweet  fruits,  -in  honey,  etc.  Artificially  it  can  be  readily 
obtained  by  heating  a  solution  of  cane-sugar  with  a  dilute  acid. 
It  is  also  formed  by  dissolving  cane-sugar  in  wine.  On  a  large 
scale  it  is  prepared  by  boiling  starch  with  very  dilute  sulphuric 
acid  for  several  hours,  neutralizing  the  liquid  with  chalk  and 
evaporating  the  solution. 

Grape-sugar  is  much  less  sweet  than  cane-sugar.  In  alco- 
hol of  90  per  Tr.  it  is  sparingly  soluble  ;  in  hot  water  it  dissolves 
in  every  proportion  ;  of  cold  water  it  requires,  however,  about 
1J-  parts  for  solution.  It  crystallizes  from  aqueous  solution 
with  one  molecule  of  water,  in  cauliflower-like  masses  and  from 
hot  alcohol  in  warty,  anhydrous  needles.  A  solution  of  crys- 
tallized grape  sugar  turns  the  plane  of  polarization  to  the 
right,  but  one  of  anhydrous  grape-sugar  to  the  left. 

Acids. — The  acid  reaction  of  fruit  juices  is  partly  due  to 
malic  acid  and  partly  to  citric  acid,  and  also  as  in  the  case  of 
grapes  to  tartaric  acid.  As  a  rule  all  these  acids  are  present ; 
in  currants  citric  acid  predominates;  in  apples,  etc.,  malic 
acid. 

The  presence  of  potassium  in  grape-must  gives  rise  to  the 
formation  of  potassium  bitartrate  of  crude  tartar.  Tartar 
requires  for  its  solution  240  parts  of  cold  water ;  in  alcoholic 
fluids  it  is  less  soluble,  and  hence  it  is  found  as  a  crystalline 
deposit  in  wine  casks.  Fruit-musts  contain  no  tartaric  acid, 
and,  consequently,  the  wines  prepared  from  them  cannot  de- 


372  MANUFACTURE    OF    VINEGAR. 

posit  tartar.  The  salts  formed  by  malic  and  citric  acids  with 
potassium  being  readily  soluble  and  even  deliquescent  form 
no  deposit  in  the  wine. 

Albuminous  substances. — By  this  general  term  are  designated 
several  nitrogenous  vegetable  substances  which  have  the  same 
composition  ;  they  being  vegetable  albumen,  fibrin,  and  glue. 
The  quantities  of  these  substances  in  the  different  musts  are, 
on  the  one  hand,  so  small,  and  the  difficulty  of  accurately  dis- 
tinguishing them  from  each  other  is,  on  the  other,  so  great, 
that  it  is  scarcely  possible  to  definitely  determine  the  kind 
actually  present  in  the  fruit  juice.  Most  likely  all  are  present 
at  the  same  time. 

For  the  preparation  of  wine  these  bodies  are  of  importance  ; 
they  furnishing  the  material  for  the  development  of  the  yeast- 
fungus  during  fermentation. 

Pectous  substances. — Under  the  heading  "  Ripening  of  fruits," 
the  pectous  substances  have  been  sufficiently  discussed.  They 
are  scarcely  ever  wanting  in  a  fruit  juice,  but  being  insoluble 
in  alcoholic  fluids  they  are  entirely  separated  with  the  yeast, 
and  hence  are  not  present  in  fruit-wines. 
''  Gum  and  Vegetable  Mucilage. — Our  knowledge  as  regards 
gum  is  still  limited.  Gum-arabic,  which  may  be  studied  as  a 
representative  of  this  class,  is  an  exudation  from  certain  species 
of  acacia  and  consists  essentially  of  arabin.  It  is  generally 
supposed  to  be  soluble  in  water,  but  on  endeavoring  to  filter  a 
somewhat  concentrated  solution  not  a  drop  will  be  found  to 
run  off,  and  the  little  which  possibly  may  pass  through  the 
filter  is  by  no  means  clear. 

Closely  related  to  gum-arabic  is  bassorine,  the  gum  which 
exudes  from  the  cherry,  plum,  almond,  and  apricot  trees.  It 
does  not  give  a  slime  with  water,  but  merely  swells  up  to  a 
gelatinous  mass. 

Wine  brought  in  contact  with  the  smallest  quantity  of  gum- 
arabic  remains  permanently  turbid  and  cannot  be  clarified  by 
filtering  or  long  standing.  From  this  behavior  of  gum  it  may 
be  concluded  that,  though  it  may  occur  dissolved  in  the  must, 
it  is  not  present  in  the  wine. 


FRUITS    AND    THEIR    COMPOSITION.  373 

The  various  kinds  of  vegetable  mucilage  have  also  not  yet 
been  accurately  examined  ;  it  only  being  known  that  there  are 
quite  a  number  of  them.  It  is,  however,  likely  that  only  a 
few  of  them  are  actually  soluble  in  water.  Though  the  muci- 
lage of  certain  seeds,  such  as  linseed  and  quince-seed,  may  be 
considered  to  be  as  soluble  in  water  as  gum-arabic,  and  per- 
haps more  so,  because  it  is  a  perfectly  clear  fluid  drawing 
threads,  yet  on  filtering  it  will  be  found  that  what  passes 
through  contains  scarcely  a  trace  of  mucilaginous  substance. 
Hence,  it  is  doubtful  whether  mucilages  exist  which  are 
actually  soluble  in  water,  and  whether  they  occur  in  wine. 
Artificial  dextrin  is,  however,  an  exception,  as  it  forms  with 
water  a  perfectly  clear  fluid,  which  can  be  filtered.  Attention 
may  here  be  called  to  an  easy  method  of  distinguishing  be- 
tween solution  of  gum-arabic  and  of  dextrin.  The  first  can- 
not be  heated,  even  for  a  minute,  over  an  open  fire  without 
scorching,  while  the  latter  can  be  completely  boiled  down 
without  fear  of  burning. 

Tannin. — Several  kinds  of  tannin  occur  in  plants,  which  can, 
however,  be  finally  reduced  to  two  modifications,  viz.:  patho- 
logical and  physiological  tannin.  The  first  occurs  in  large 
quantity  in  nut-galls,  especially  in  the  Chinese  variety,  also  in 
sumach  (the  twigs  of  Rhus  coriaria)  and  in  many  other  plants. 
Pathological  tannin  is  characterized  by  splitting  under  the 
influence  of  dilute  acids  as  well  as  by  fermentation  into  gallic 
acid  and  grape-sugar.  Furthermore,  it  completely  precipitates 
glue  from  its  solutions,  but  it  is  not  suitable  for  the  conversion 
of  the  animal  skin  into  technically  serviceable  leather  which 
will  withstand  putrefaction.  Besides,  only  the  gallic  acid 
obtained  from  pathological  tannin  yields  pyrogallic  acid  by 
destructive  distillation. 

Physiological  tannin  is  chiefly  found  in  materials  used  for 
tanning.  It  cannot  be  split  by  dilute  acids  or  fermentation, 
does  not  yield  gallic  acid,  and  the  product  of  destructive  dis- 
tillation is  not  pyrogallic  acid,  but  pyrocatechin  or  oxyphenic 
acid.  It  converts  the  animal  skin  into  perfect  leather. 


374  MANUFACTURE    OF    VI^GAR. 

There  can  be  but  little  doubt  that  physiological  tannin  is 
the  variety  found  in  fruits  and  fruit-juices.  Generally  speak- 
ing, a  content  of  tannin  in  wine  is  not  exactly  a-  desirable 
feature,  as  it  is  readily  decomposed.  It  can  only  have  an  ad- 
vantageous effect  when  the  wine  contains  an  excess  of  albumin" 
ous  substances  which  the  tannin  removes  by  entering 
into  insoluble  combinations  with  them.  This  may  be  the 
reason  why  wine  containing  tannin  is  considered  more  dura- 
ble, because  if  it  contained  albuminous  substances  in  large 
quantity  it  would  be  still  more  readily  subjected  to  changes. 
Under  such  circumstances  a  small  addition  of  tannin  to  the 
wine  may  be  of  advantage,  though  instead  of  tannin  it  is 
advisable  to  use  an  alcoholic  extract  of  grape-stones,  they  being 
uncommonly  rich  in  tannin. 

Inorganic  constituents. — The  inorganic  constituents  of  the 
different  varieties  of  fruit  are  very  likely  the  same,  namely, 
potash,  lime,  magnesia,  and  sulphuric  and  phosphoric  acids, 
they  varying  only  in  the  proportions  towards  one  another  and 
in  the  total  quantity  of  all  the  substances.  Moreover,  their 
quantity  is  too  small  to  exert  an  influence  upon  the  quality  of 
the  wine  to  be  produced,  being  of  interest  only  in  regard  to 
the  exhaustion  of  the  soil.  Though  lime  and  sulphuric  acid  in 
sufficient  quantity  occur  almost  everywhere  in  the  soil,  this 
cannot  be  said  of  potash  and  phosphoric  acid.  Unfortunately 
there  are  no  accurate  statements  regarding  the  amount  of  these 
substances  which  is  withdrawn  from  the  soil  by  the  crop  of  one 
year,  but  there  can  be  no  doubt  that  it  is  very  large,  and  that 
consequently  fruit  trees  from  time  to  time  require  a  certain 
amount  of  manure  in  order  to  return  to  the  soil  what  has  been 
taken  from  it. 

Fermentation. — Fermentation  is  a  chemical  process  which  is 
always  caused  by  the  presence  of  a  ferment  or  a  substance  in  a 
peculiar  state  of  decomposition.  Although  to  induce  fermen- 
tation the  presence  of  a  ferment  is  necessary,  it  does  not  take 
part  in  the  decomposition  of  the  fermenting  substance.  The 
products  of  fermentation  vary  according  to  the  nature  of  the 


FRUITS    AND    THEIR    COMPOSITION.  375 

fermenting  body,  as  well  as  according  to  the  nature  of  the  fer- 
ment itself.  Each  peculiar  kind  of  fermentation  requires  a 
certain  temperature,  and  it  is  nearly  always  accompanied  by 
the  development  of  certain  living  bodies  (bacteria  or  fungi). 

.When  yeast  is  added  to  a  dilute  solution  of  dextrose  or 
another  glucose,  vinous  fermentation  speedily  sets  in ;  whilst  a 
solution  of  cane-sugar  undergoes  fermentation  but  slowly,  the 
cause  being  that  this  sugar  must  first  be  converted  into  inverted 
sugar  before  fermentation  can  commence.  Vinous  fermenta- 
tion proceeds  most  rapidly  at  77°  to  86°  F.,  and  does  not  take 
place  below  32°  or  above  95°  F.  The  presence  of  a  large 
quantity  of  acids  or  alkalies  prevents  fermentation,  while  if  the 
liquid  has  a  faint  acid  reaction,  fermentation  proceeds  best. 

The  yeast  which  is  formed  in  the  fermentation  of  the  juice 
of  grape  and  other  kinds  of  fruit  is  produced  from  soluble  albu- 
minous bodies  contained  in  fruit.  It  consists  of  one  of  the 
lowest  members  of  the  vegetable  kingdom  (Torula  cerewsise)^ 
and  under  the  microscope  is  seen  to  be  made  up  of  little  oval 
transparent  globules,  having  a  diameter  of  not  more  than  0.1 
millimeter  and  often  adhering  in  clusters  and  strings.  They 
are  propagated  by  budding,  and  die  as  soon  as  they  have 
reached  their  highest  state  of  development.  In  contact  with 
air  and  water  yeast  soon  undergoes  putrefaction. 

The  chief  products  of  vinous  fermentation  are  alcohol  and 
carbon  dioxide ;  a  small  quantity  of  the  sugar  being  at  the 
same  time  converted  into  other  products,  about  2.5  per  cent, 
being  transformed  into  glycerin  and  0.6  to  0.7  per  cent,  into 
succinic  acid.  A  further  portion  of  the  sugar,  about  one  per 
cent.,  is  assimilated  in  the  form  of  cellulose  by  the  yeast  and 
separated.  By  the  simultaneous  formation  of  these  different 
secondary  products  about  5.5  to  6.5  per  cent,  of  sugar  is  lost 
in  the  formation  of  alcohol.  As  they  are  not  always  formed 
in  equally  large  quantities,  no  conclusion  can  be  arrived  at 
from  the  content  of  sugar  in  the  must  as  to  the  quantity  of 
alcohol  corresponding  to  theory  in  the  finished  wine.  It  is, 
as  a  rule,  supposed  that  the  sugar  yields  one-half  its  weight 


376  MANUFACTURE    OP    VINEGAR. 

of  alcohol,  which  is  sufficiently  correct  for  all  practical  pur- 
poses. 

Absolute  alcohol,  i.  e.,  alcohol  entirely  free  from  water,  is  a 
very  mobile  fluid,  clear  as  water  and  almost  odorless.  It  boils 
at  173°  F.,  and  when  it  is  cooled  down  to  148°  F.  it  becomes 
viscid,  but  does  not  solidify.  Its  specific  gravity  at  32°  F.  is 
0.80625,  and  at  59°  F.  0.79367.  It  is  very  inflammable,  and 
burns  with  a  blue,  non-luminous  flame.  It  absorbs  moisture 
with  great  avidity,  and  is  miscible  with  water  in  all  propor- 
tions, the  mixture  evolving  heat  and  undergoing  contraction. 

The  methods  for  determining  the  content  of  alcohol  in  a 
fluid  have  already  been  previously  given. 

Sucdnic  add. — No  accurate  researches  have  as  yet  been 
made  in  regard  to  the  quantity  of  this  acid  in  wine,  its  influ- 
ence upon  the  quality  of  the  wine,  and  the  conditions  under 
which  more  or  less  of  it  is  formed  during  fermentation.  Ac- 
cording to  Pasteur,  the  more  succinic  acid  is  formed  the  slower 
fermentation  progresses;  the  weaker  the  development  of  yeast 
and  the  less  nourishment  offered  to  the  latter.  In  acid  fluid 
more  succinic  acid  is  formed  than  in  neutral. 

Succinic  acid  is  quite  readily  soluble  in  a  mixture  of  alcohol 
and  water,  and  consequently  also  in  wine.  Its  taste  is  not 
very  sour,  but  disagreeable,  and  adheres  for  some  time  to  the 
tongue ;  hence  its  presence  can  scarcely  be  expected  to  give 
an  agreeable  taste  to  the  wine. 

Glycerin. — Glycerin  being  found  in  grape-wines,  in  which 
it  is  formed  from  the  sugar  by  fermentation,  there  can  scarcely 
be  any  doubt  of  its  formation  under  the  same  conditions  in 
fruit  wines.  According  to  Pasteur,  the  quantity  of  glycerin 
in  wine  is  in  a  definite  proportion  to  the  succinic  acid  formed, 
and,  hence,  more  glycerin  would  be  produced  with  slow  fer- 
mentation and  in  an  acid  fluid.  In  red  wines  Pasteur  found 
4  to  7  per  cent,  of  glycerin. 

Pure  glycerin  is  a  colorless,  very  viscid  liquid  having  a  spe- 
cific gravity  of  1.27.  It  can  be  mixed  with  water  and  alco- 
hol in  all  proportions  and  possesses  a  very  sweet  taste.  It  is 


FRUITS    AND    THEIR    COMPOSITION.  377 

very  likely  that  the  mild  sweet  taste  of  many  ripe  wines  is  due 
to  a  certain  content  of  glycerin. 

A  solution  of  7  parts  of  glycerin  in  1000  of  water  (the  pro- 
portion in  which  Pasteur  found  glycerin  in  wine)  does  not 
possess  a  sweet  taste  and  differs  from  water  only  in  being  more 
insipid.  By  adding  to  such  a  solution  100  parts  of  alcohol, 
the  mixture  shows  a  taste  different  from  that  of  alcohol  alone, 
diluted  in  the  same  proportion,  the  predominant  taste  of  the 
latter  being  decreased  by  the  glycerin  and  that  of  the  mixture 
becoming  milder.  Hence  a  certain  importance  has  to  be  as- 
cribed to  the  glycerin. 

Carbonic  acid. — The  greater  portion  of  the  carbonic  acid 
formed  by  fermentation  escapes  as  a  gaseous  body  during  the 
process,  but  a  certain  portion  remains  dissolved  in  the  wine  as 
long  as  the  temperature  of  the  latter  is  not  raised.  The  tem- 
perature of  cellars  generally  increases,  however,  towards  the 
end  of  spring,  which  causes  anew  a  slight  development  of  car- 
bonic acid  in  consequence  of  which  the  wine  again  becomes 
turbid.  The  presence  of  carbonic  acid  is  of  advantage  only  in 
young  wine,  as  its  protects  it  from  the  direct  action  of  the  air 
by  forming  a  layer  upon  the  surface.  In  old  wines  it  conceals, 
however,  the  fine  aroma  and  taste,  making  them  appear 
younger  than  they  actually  are. 

Though  it  cannot  be  said  that  carbonic  acid  plays  an  essen- 
tial part  in  the  preparation  of  wine,  it  deserves  attention  on 
account  of  its  deleterious  influence  upon  the  workmen.  To 
avoid  all  injurious  consequences,  provision  should  be  made 
for  a  thorough  ventilation  of  the  cellar  by  means  of  windows 
and  doors.  If  fermentation  is  carried  on  in  barrels,  the  car- 
bonic acid  developed  in  a  number  of  them  should  be  conducted 
by  means  of  tubes  secured  air-tight  in  the  bungs  to  a  zinc  pipe 
which  passes  through  a  suitable  aperture  into  the  open  air. 

Alkaloid  in  wine. — It  has  frequently  been  asserted  that  an 
alkaloid  exists  in  young  wine,  which  not  being  contained  in 
the  must  or  the  yeast  must  have  been  formed  from  the  nitro- 
genous constituents  of  the  yeast  or  of  the  fluid  during  fermen- 


378  MANUFACTURE    OF    VINEGAR. 

tation.  It  has  not  been  found  in  old  wine,  and  it  is  therefore 
concluded  that  it  in  time  decomposes.  Should  this  observation 
be  confirmed,  it  would  explain  the  difference  in  the  effects  of 
the  very  intoxicating  young  wines  and  of  old  wines. 


CHAPTER  XXIX. 

MANUFACTURE    OF    CIDER. 

THE  first  step  in  the  preparation  of  fruit-wines  is  to  obtain 
the  juice  or  must  from  the  fruit.  Stamping  or  grinding  and 
subsequent  expressing  of  the  paste  thus  formed  by  means 
of  strong  pressure  suffice  in  most  cases  for  berries  and  other 
small  fruits.  With  apples,  etc.,  this  manner  of  reduction  is 
not  only  difficult,  but  also  connected  with  considerable  loss 
caused  by  larger  and  smaller  pieces  jumping  from  the  trough. 

The  earliest  appliance  known  was  simply  a  trough  in  which 
the  apples  were  reduced  to  an  imperfect  pomace  by  rolling 
them  with  a  heavy  cylindrical  stone  or  by  pounding  them  as 
in  a  mortar.  An  improvement  was  the  production  of  the 
English  cider-mill.  This  consisted  of  a  pair  of  coarsely  cor- 
rugated iron  cylinders  from  which  the  apples  fell  to  a  second 
pair  close  together  and  finer  in  their  surfaces,  and  passed 
through  finely  mashed  to  the  pomace  vessel  underneath.  In 
1852,  Mr.  W.  0.  Hickock,  of  Harrisburg,  Pa.,  invented  a 
portable  cider-mill  which  consisted  of  a  pair  of  small  horizon- 
tal cylinders  armed  with  small  spirally  arranged  teeth  or  spikes 
revolving  close  together,  one  at  a  higher  velocity  than  the 
other.  The  apples  were  first  broken  by  the  action  of  a 
coarsely-fluted  roller  which  revolved  against  a  table  under 
the  hopper,  and  after  passing  between  the  cylinders,  the  apples 
were  not  only  bruised  but  also  grated  into  the  required  pomace. 
This  machine  was  capable  of  grinding  100  bushels  of  apples 
per  day.  Numerous  modifications  have  been  made  in  the 


MANUFACTURE    OF    CIDER.  379 

plan  of  Mr.  Hickock's  mill,  some  being  simply  spiked  cylinders 
against  which  the  apples  were  carried  and  held  till  grated  by 
reciprocating  plungers. 

The  limits  of  this  work  will  not  permit  of  a  notice  of  all 
the  various  styles  of  portable  mills  before  the  public  or  the 
multitude  of  graters  or  apple  grinders,  many  of  which  possess 
excellent  points  and  are  worthy  of  commendation.  An  excel- 
lent apparatus  for  crushing  apples  is  the  crushing-mill  shown 
in  Figs.  90  and  91,  B  C  (Fig.  91)  representing  the  cylinders 
provided  with  teeth.  A  hopper,  A,  receives  the  apples,  which 
pass  between  the  cylinders,  where  they  are  crushed  and  fall 

FIG  90.  FIG.  91.  • 


into  the  receiver  F  placed  underneath.  Two  men  operate 
this  mill  by  means  of  cranks.  Larger  and  stronger  mills  are 
used  when  the  quantity  of  apples  seems  to  require  them,  and 
in  that  case  horse-power  is  applied. 

Fig.  92  shows  Davis's  star  apple-grinder.  The  grinder 
shown  in  the  illustration  is  a  heavy  machine  weighing  340 
Ibs.  The  cylinder  is  12  inches  in  diameter  and  12  inches  long, 
is  turned  and  carefully  balanced,  has  grooves  planed  in  to 
receive  the  knives,  six  in  number,  which  are  finely  made  and 
tempered.  Each  knife  furnished  is  made  of  steel-plated  iron, 
the  steel  being  very  thin  and  having  a  back  of  iron  ;  there 


380  MANUFACTURE    OF    VINEGAR. 

is  no  danger  of  breaking,  although  made  very  hard.  The 
end  of  the  cylinder  is  banded  with  wrought-iron  bands 
and  the  knives  are  set  with  set- screws.  The  shaft  is  of  steel 
and  runs  in  anti-friction  metal.  The  concaves  are  hung  at 
top,  so  they  can  swing  back  at  the  bottom  to  allow  stone,  pieces 
of  iron,  etc.  to  pass  through  without  injuring  the  knives.  The 
concaves  are  held  to  their  places  by  a  bolt  which  allows  the 
concave  to  be  set  as  close  as  desired  to  the  cylinder,  and  is 
held  to  its  place  by  coil-springs  which  will  give  enough  to 
allow  stones  to  pass  and  yet  hold  rigid  in  grinding  even  fro- 
zen apples.  The  frame  is  one  casting,  and  as  the  concaves 


are  fast  to  the  frame  they  cannot  get  out  of  line  or  be  dis- 
placed, as  in  the  case  when  the  concave  is  fast  to  the  hopper. 
The  hopper  can  be  readily  removed  to  adjust  knives,  and  all 
parts  are  adjustable  and  easy  to  get  at.  This  machine  can  be 
gauged  to  grind  from  200  to  400  bushels  per  hour.  Power 
required  to  grind  six  bushels  per  minute,  about  six  horse-power, 
say  about  as  many  horse-power  as  desired  to  grind  bushels  per 
minute. 

Presses. — For  obtaining  the  juice  from  berries,  etc.,  a  press 
is  generally  not  required,  or  at  least  only  a  slight  pressure  ; 
the  greater  portion  of  it  running  out  from  the  must  by  placing 


MANUFACTURE    OF    CIDER. 


381 


the  latter  upon  a  cloth  spread  over  a  perforated  bottom  in  a 
vat.  The  juice  retained  by  the  lees,  which,  as  a  rule,  is  very 
sour  and  has  to  be  diluted  with  water,  can  be  extracted  with 
the  latter  more  completely  than  is  possible  with  the  strongest 
press. 

For  obtaining  the  juice  from  apple  pomace,  etc.  a  good  press 
is,  however,  an  important  auxiliary.  Before  the  introduction 
of  screws  the  method  of  extracting  the  juice  of  the  apple  was 
by  the  use  of  heavy  weights,  wedges,  and  leverage.  Until 
within  a  late  period  a  large  wooden  screw  was  used  and  is  even 
now  employed  in  some  sections  of  the  country.  Of  these 
screws  two  and  frequently  three  and  four,  set  in  a  strong  frame- 
work of  double  timbers,  were  found  no  more  than  sufficient  to 
separate  the  cider  from  the  pomace.  In  order  to  operate  these 
screws  a  long  heavy  wooden  lever  became  necessary,  which 
required  the  united  services  of  four  or  five  men  to  handle,  and 
not  unfrequently  the  strength  of  a  yoke  of  oxen  was  called 
into  requisition  before  the  work 
could  be  accomplished.  An  im- 
provement upon  the  wooden  screw 
was  made  by  the  substitution  of 
the  iron  screw  and  iron  nut.  But 
the  objectionable  feature  of  hav- 
ing to  handle  heavy  and  cumber- 
some levers  still  remained,  mak- 
ing labor  irksome  and  expensive. 
In  modern  presses  this  difficulty 
has  been  entirely  overcome,  and 
the  juice  is  extracted  from  the 
pomace  with  great  ease  and  com- 
pleteness. 

Of  the  many  presses  before  the 
public,  a  hand-press  a-nd  a  power- 
press  are  here  illustrated  ;  presses  of  all  sizes  between  these 
two  are  found  in  the  market.     Fig.  93  shows  the  "  Farmer's 
cider-press."     It  is  7  feet  1  inch  high,  with  a  width  between 


Fig.  93. 


MANUFACTURE    OP    VINEGAR. 

the  rods  of  3  feet  If  inches.  It  will  hold  15  to  16  bushels  of 
apples  at  a  pressing  and  is  especially  designed  for  individual 
use.  It  is  also  admirably  adapted  for  squeezing  the  juice  from 
small  fruits,  berries,  etc. 

Fig.  94  shows  the  "  Extra  power  cider-press,"  with  revolv- 
ing platform.     It  is  13  feet  4  inches  high,  6  feet  4  inches  wide 

FIG.  94. 


between  the  rods,  and  has  a  platform  13  feet  3  inches  long. 
It  gives  a  pressure  of  250  tons.  The  press  is  always  loaded 
in  one  place,  and  consequently  the  grater  can  be  located 
immediately  over  the  middle  of  the  cheese,  avoiding  the 
necessity  of  conveying  the  pomace  from  one  end  of  the  press 


MANUFACTURE    OF    CIDER. 


383 


to  the  other.     This  press  can  easily  make  a  pressing  of  12 
barrels  of  cider  each  hour. 

Fig.  95  shows  the  revolving  platform  belonging  to  the 
above  press,  for  which  the  following  advantages  are  claimed  : 
1.  Both  ends  of  the  platform  are  loaded  and  unloaded  in  the 
same  place.  2.  It  is  so  geared  that  one  man  can  easily  and 
quickly  revolve  it.  3.  The  grinder  can  be  directly  over  the 
centre  of  the  cheese,  thus  avoiding  all  the  labor  of  shoveling 
the  pomace.  4.  The  pomace  being  dropped  in  the  centre  of 
the  cheese,  it  is  an  easy  matter,  to  spread  it  with  equal  density 
over  the  entire  surface,  thus  building  a  cheese  that  is  not 
liable  to  tilt  or  slide.  The  cider  runs  into  a  copper  basin  in 


the  centre  of  the  platform  between  the  two  cheeses.  The  basin 
is  so  arranged  that  it  receives  the  cider  while  the  platform  is 
being  revolved  as  well  as  while  the  press  is  working. 

A  is  the  copper  basin-  to  receive  the  cider  from  platforms, 
and  has  an  outlet  through  the  bottom,  about  6  inches  in  diam- 
eter, for  the  cider  to  pass  off  into  the  tank  below.  B  is  a  cop- 
per tube  encasing  the  rods.  C,  (7,  C,  C  are  four  posts  fastened 
to  the  platform  to  hold  guide-pieces  for  racks.  D,  D  are  rack 
guides. 

Improved  Racks. — The  single  racks  are  made  of  some  light 
and  tough  wood — bass-wood  or  spruce  seems  best — cut  into 
strips  about  JXJ  inch  and  placed  about  J  inch  apart,  with 


384  MANUFACTURE    OF    VINEGAR. 

four,  five,  or  more  elm  strips,  2  inches  wide  about  f  inch  thick, 
placed  across  and  nailed  to  the  narrow  slats.  The  2-inch  slats 
extend  beyond  the  narrow  ones  on  each  side  about  4  inches. 
This  is  to  support  the  wings,  which  are  fastened  to  the  rack 
by  3  or  more  bronze  hinges.  These  wings,  with  the  aid  of  2 
retaining  bars,  make  the  box  to  form  the  pomace  in.  The  slats 
are  rounded  on  the  edges,  so  as  not  to  injure  the  press-cloth. 
Steel  wire  nails  or  wire  staples  are  used  of  sufficient  length  to 
clinch. 

Double  racks  are  made  by  using  slats  -ft- Xf  inch.  The  slats 
on  one  side  are  laid  directly  across  the  slats  on  the  other  side. 
Four  wide  slats  are  put  at  the  outer  edges,  then  these  are  all 
fastened  together  by  steel  wire  nails  or  staples.  These  racks 
have  the  advantage  of  having  an  even  surface  on  each  side. 
The  press-cloth  will  last  much  longer  than  when  used  on  single 
racks,  where  it  is  strained  over  4  to  9  elm  slats. 

To  lay  up  a  cheese  with  the  improved  rack,  commence  on 
the  platform  of  the  press  and  lay  a  rack  ;  then  turn  up  the 
wings  on  each  side  of  the  rack  and  place  the  retaining  bars  on 
each  end,  with  the  hooks  on  the  outside  of  the  wings,  so  as  to 
hold  them  up.  Over  this  box  spread  the  cloth,  fill  the  box 
evenly  full  of  pomace,  then  turn  in  the  sides  and  ends  of  the 
cloth  over  the  pomace,  the  cloth  being  of  sufficient  size  to 
cover  it.  The  retaining  bars  are  then  removed,  allowing  the 
wings  to  fall  in  place.  Another  rack  is  placed  on  the  cheese 
just  made,  the  retaining  bars  placed  in  position  to  hold  up  the 
wings,  another  cloth  placed  on  the  box,  etc.,  and  this  opera- 
tion is  continued  until  there  is  the  right  number  of  layers  in 
the  press.  A  rack  should  be  placed  on  the  top  of  the  last  layer. 
A  guide  should  be  used  in  laying  up  the  cheese,  so  as  to  bring 
each  rack  directly  above  the  other. 

Plain  racks.- — These  are  made,  either  single  or  double,  of 
slats  of  the  same  description  and  dimensions  as  are  used  in  the 
improved  racks,  but  in  the  place  of  wings  and  retaining  bars, 
a  form  square  in  size  and  4  inches  deep  is  used  to  form  the 
sides  of  a  box  for  the  pomace.  In  laying  up  a  cheese  com- 


MANUFACTURE    OF    CIDER.  385 

mence  by  placing  a  rack  on  the  platform,  and  upon  this  place 
the  form,  spread  a  cloth  over  the  form  and  fill  even  up  with 
pomace ;  then  fold  the  ends  and  sides  of  the  cloth  over  onto 
the  pomace,  as  described  with  the  other  style  of  rack,  and 
remove  the  form.  Place  another  rack  on  the  layer  just  formed, 
and  put  the  form  on  that  and  proceed  as  before  until  the 
cheese  is  complete.  It  will  require  one  cloth  less  than  the 
number  of  racks  used  for  a  cheese.  Care  must  be  exercised  in 
laying  a  cheese  to  have  the  racks  come  evenly,  as  they  are 
liable  to  tilt  if  they  overhang.  The  best  way  to  avoid  the 

FIG.  96. 


liability  to  slide  or  tilt  is  to  lay  the  racks  alternately  the  length 
and  breadth  of  the  press. 

In  the  equipment  of  a  first-class  modern  cider  mill  nothing 
gives  better  satisfaction  for  the  money  expended  than  an 
apple  elevator.  The  expense  is  a  small  matter  compared  with 
the  convenience  of  having  the  mill  so  arranged  that  apples 
may  be  brought  from  any  part  by  a  perfect  working  elevator 
and  carrier.  Fig.  96  shows  a  section  of  an  elevator.  The 
chain  runs  over  and  is  operated  by  a  sprocket  gear  at  the 
head  with  fast  and  loose  pulleys.  The  scrapers  are  of  wood, 
25 


386 


MANUFACTURE    OF    VINEGAR. 


3  inches  wide  and  11 J  inches  long,  bolted  to  lugs  or  projections 
on  the  chain.  When  run  at  from  50  to  70  revolutions  per 
minute  it  will  elevate  from  5  to  10  bushels  per  minute.  It 
works  at  an  inclination  or  carries  on  the  level. 

Fig.  97  shows  the  arrangement  of  a  plant  for  making  cider 
on  a  large  scale,  as  described  by  Paul  Hassack.*  The  apples 
are  shoveled  direct  from  the  vehicle  in  which  they  are  brought 
to  the  plant  into  the  shed  A,  which  is  divided  into  not  too 
large  compartments.  It  is  not  advisable  to  pile  the  apples 
more  than  3  to  4J  feet  high,  as  otherwise,  when  the  weather  is 

FIG.  97. 


unfavorable,  the  entire  pile  may  become  heated,  and  rotting, 
browning  or  the  formation  of  acetic  acid  set  in.  Alongside 
the  shed  runs  up  to,  underneath  the  roof  of  the  press-room 
the  elevator  B,  which  conveys  the  apples  to  the  grinder  0, 
the  finely  ground  pulp  falling  into  the  receptacle  D.  The 
latter  is  furnished  with  a  wooden  tube  E  which  can  be  closed, 
and  leads  to  the  press-room.  By  opening  a  slide  a  quantity 
of  pulp  just  sufficient  for  one  layer  is  allowed  to  run  from  the 

* ' '  Garungs-Essig." 


MANUFACTURE    OF    CIDER.  387 

tube.  F  is  a  press-platform  equipped  with  wheels  and  run- 
ning on  a  track.  Upon  this  the  pulp  is  uniformly  spread, 
layer  upon  layer,  each  layer  enclosed  in  a  press  cloth  and  a 
rack  between  each  layer.  According  to  the  size  of  the  press 
eight  to  twelve  such  layers  are  made  into  a  cheese.  The  plat- 
form is  then  pushed  under  the  press  G,  which  is  put  in  action 
by  the  motor  M.  In  the  commencement  of  the  operation 
pressing  has  to  be  done  carefully  and  not  too  suddenly  to 
avoid  bursting  the  press  cloths,  a  more  powerful  pressure 
being  applied  only  towards  the  end  of  the  process  when  the 
juice  runs  off  more  slowly.  In  the  meanwhile  the  next 
cheese  is  prepared. 

Testing  the  Must  as  to  its  Content  of  Acid  and  Sugar. — With 
the  exception  of  the  grape  but  few  varieties  of  fruit  contain 
acid  and  sugar  in  such  proportions  and  in  such  quantity  (gen- 
erally too  much  acid  and  too  little  sugar)  in  that  the  must  ob- 
tained from  them  will  yield,  when  subjected  to  fermentation, 
a  drinkable  and  durable  wine.  Wine  whose  content  of  acid 
exceeds  1  per  cent,  is  too  sour  to  the  taste,  and  one  containing 
less  than  5  per  cent,  of  alcohol  cannot  be  kept  for  any  length 
of  time.  Now  as  all  fruit  wines  may  be  called  artificial 
wines,  and  a  natural  product  has  consequently  to  be  improved 
in  order  to  make  it  more  agreeable  and  wholesome,  it  is  nec- 
essary to  find  ways  and  means  by  which  the  object  can  be 
accomplished  in  a  manner  most  conformable  to  nature.  For 
this  purpose  a  knowledge  of  the  content  of  acid  and  sugar  in 
the  fruit-must  is  required. 

To  find  the  quantity  of  acid,  compound  a  determined  quan- 
tity, about  50  cubic  centimetres,  of  must  with  about  5  grammes 
of  purified  animal  charcoal,*  boil  the  mixture  about  five 
minutes,  and  after  cooling  replace  the  exact  quantity  of  water 
lost  by  evaporation.  After  shaking  bring  the  whole  upon  a 

*Bone-black  which  is  first  boiled  with  solution  of  sodium  carbonate  for  some 
time,  and  then  after  washing  and  extracting  with  hydrochloric  acid  is  again 
washed  and  dried. 


388  MANUFACTURE    OF    VINEGAR. 

coarse  paper-filter  in  a  glass  funnel ,  and  let  it  run  off.  Of  the 
clear  and  generally  colorless  filtrate  bring  6.7  cubic  centimeters 
into  a  small  beaker,  add  sufficient  distilled  water  to  form  a 
layer  of  fluid  2  to  3  centimeters  deep,  and  color  red  with  5  to 
10  drops  of  litmus  tincture.  While  holding  the  beaker  in  the 
left  hand  and  constantly  moving  it  slowly  in  a  horizontal 
direction,  allow  to  run  or  drop  in  from  a  pipette,  graduated  in 
TV  cubic  centimeters  and  filled  to  the  0-mark,  decinormal 
liquid  ammonia  until  the  last  drop  no  longer  changes  the 
color  of  the  fluid,  and  the  place  where  the  drop  falls  appears 
as  if  made  clear  by  a  drop  of  water.  Now  prevent  a  further 
flow  of  the  ammonia  by  closing  the  pipette  with  the  index 
finger  of  the  right  hand,  and  read  off  the  quantity  of  ammonia 
consumed.  The  must  examined  contains  as  many  thousandths 
of  malic  acid  as  cubic  centimeters  of  liquid  ammonia  were 
required  to  color  the  fluid  blue. 

Now  if  the  examination  shows  that  a  must  contains  more 
than  8  parts,  of  acid  per  thousand,  it  is  evidently  too  sour  for 
the  preparation  of  a  palatable  and  wholesome  fruit  wine,  and 
hence  must  be  diluted  to  such  a  degree  as  to  reduce  the  con- 
tent of  acid  to  6  or  at  the  utmost  to  8  parts  per  thousand.  The 
calculation  for  this  dilution  is  very  simple,  and  consists  in 
multiplying  the  acid  per  thousand  parts  present  by  100  and 
dividing  with  the  content  of  acid  the  wine  is  to  have,  the  entire 
volume  containing  the  desired  acid  per  thousand  being  thus 
obtained.  If,  for  instance,  18  parts  per  thousand  of  acid  have 
been  found  in  currant-must  and  the  wine  is  only  to  show  6J 

parts  per  thousand,  then  1QO  X  18 .=  276.923,  in  round  num- 

6J 

bers  —  277,  i.  e.,  277  parts  by  measure  of  water  have  to  be 
added  to  every  100  parts  by  measure  of  must. 

The  content  of  acid  in  the  must  thus  forms  the  initial  point 
for  the  dilution  in  order  to  obtain,  after  fermentation,  wine 
with  a  determined  quantity  of  acid.  To  be  sure  the  content 
of  acid  is  sometimes  increased  by  fermentation,  some  succinic 
acid,  as  previously  mentioned,  being  formed  and  perhaps  also 


MANUFACTURE    OF    CIDER.  389 

some  acetic  acid.  Sometimes,  however,  the  content  of  acid 
decreases,  which  is  very  likely  partially  due  to  the  water  used 
for  the  dilution  of  the  must  containing  earthy  carbonates 
(lime,  magnesia).  It  is,  therefore,  best  not  to  have  too  much 
acid  in  the  must,  since,  if  the  finished  wine  should  be  lacking 
in  acid,  it  can  readily  be  remedied  by  a  suitable  addition  of 
tartaric  acid,  which  is,  however,  not  the  case  when  it  contains 
too  much  free  acid. 

The  determination  of  the  sugar  in  must  presents  less  diffi- 
culty and  has  already  been  fully  described,  hence  there  re- 
mains only  the  question  how  much  sugar  has  to  be  added 
to  the  must  in  order  to  obtain  a  durable  wine. 

Numerous  analyses  have  shown  that  there  is  scarcely  any 
grape  wine  which  contains  less  than  7  per  cent,  by  weight  of 
alcohol,  while  in  more  generous  wines  the  content  rises  to  12 
per  cent,  and  more.  Fruit-wines  in  order  to  possess  good 
keeping  properties  should  never  show  less  than  7  per  cent,  by 
weight  of  alcohol,  but  there  is  no  reason  why  they  should  not 
contain  as  much  as  10  per  cent.  The  advantage  of  the  latter 
content  is  evident,  the  wines  being  thereby  almost  absolutely 
protected  from  spoiling,  while  they  improve  in  aroma  and 
taste,  the  various  kinds  of  ether  being  only  formed  in  wine 
rich  in  alcohol. 

The  manner  of  calculating  the  quantity  of  sugar  which  has 
to  be  added  to  the  must  to  give  the  wine  the  desired  content 
of  alcohol,  wrill  be  best  shown  by  the  following  example :  Sup- 
pose 135  liters  of  must  which  contains  4  per  cent,  of  sugar  are 
to  be  changed  into  must  with  15  per  cent,  of  sugar. 

For  this  purpose  deduct  from  the  weight  of  the  must  (which 
for  the  sake  of  simplicity  we  will  consider  equal  to  its  volume) 
the  weight  of  the  sugar  contained  therein,  multiply  by  the 
difference  the  per  cent,  of  sugar  the  must  is  to  contain,  divide 
the  product  by  100  less  the  per  cent,  of  sugar,  and  deduct 
from  the  quotient  the  per  cent,  of  sugar  already  present  in  the 
must.  For  instance  :  135  liters  of  must  with  4  per  cent,  of 
sugar  are  to  be  changed  into  must  with  15  per  cent,  of  sugar. 


390  MANUFACTURE    OF    VINEGAR. 

In  135  liters  are  contained  6.4  kilogrammes  of  sugar;  135  — 
5.4  =  129.6,  which  multiplied  by  15=1944;  this  number 
divided  by  100  —  15  =  85  gives  22.87.  Deduct  from  this  5.4, 
and  there  remain  17.47  kilogrammes  of  sugar  which  have  to 
be  added  to  the  must  to  give  it  15  per  cent,  of  sugar. 

For  325  liters  of  must  with  3J  per  cent,  of  sugar  to  be 
changed  into  must  with  20  per  cent,  of  sugar  the  calculation 
would  be  as  follows  : 

(325  —  11.375)20  =  313.625  X  20  = 
100  —  20  ~8QT 

01  q  ftOK 

^pD  =  78.406  —  11.375  =  67.03  kilogrammes  of  sugar  to 

be  added. 

600  liters  of  must  with  6  per  cent,  of  sugar  are  to  be  changed 


.. 

into  must  with  22  per  cent,  of  sugar  :  _l    —  36  =  117.4 

39 

kilogrammes  of  sugar. 

The  above  examples  will  suffice  to  enable  any  one  to  exe- 
cute the  calculations  as  required. 

The  above  calculations  are  based  upon  pure,  anhydrous 
grape  sugar,  an  article  which  does  not  exist  in  commerce,  and 
hence  has  to  be  replaced  either  by  commercial  grape-sugar 
(glucose)  or  cane-sugar.  Glucose,  however,  containing  as  a 
rule  only  67  per  cent,  of  anhydrous  grape-sugar,  1  J  times  the 
quantity  calculated  above  must  be  used,  thus  in  the  last  ex- 
ample 176  kilogrammes  instead  of  117.4.  With  cane-sugar 
the  proportion  is  the  reverse,  171  parts  by  weight  of  cane-sugar 
being  equal  to  180  parts  by  weight  of  anhydrous  grape-sugar; 
hence  the  per  cent,  of  anhydrous  grape-sugar  calculated  accor- 
ding to  the  above  method  must  be  multiplied  by  the  fraction 
TyT  or  the  factor  0.95.  According  to  this,  instead  of  the  117.4 
kilogrammes  of  grape-sugar  in  the  last  example,  111.73  kilo- 
grammes of  cane-sugar  will  have  to  be  used. 

Glucose.  —  Pure  glucose  being  identical  with  the  sugar  in 
sweet  fruits,  its  use  for  sweetening  fruit-juices  intended  for  the 


MANUFACTURE    OF    CIDER.  391 

preparation  of  wine  is  perfectly  justifiable.  With  the  dispute 
still  carried  on  with  honest  weapons,  whether  it  is  permissible 
to  assist  nature  with  glucose  when  it  fails  to  succeed  in  its  labor 
of  forming  sugar  in  abundance,  we  have  here  nothing  to  do, 
since  we  know  that  the  principal  product — alcohol  or  spirits  of 
wine — and  almost  the  only  one  which  passes  into  the  wine  by 
the  fermentation  of  sugar,  possesses  the  same  properties  whether 
it  be  formed  from  fruit-sugar  or  from  glucose,  and  that  neither 
one  or  the  other  can  be  injurious  to  health  in  the  state  of  dilu- 
tion in  which  it  presents  itself  in  the  wine,  provided  the  latter 
be  used  in  moderation.  The  must  might  be  sweetened,  as  is 
frequently  done,  with  cane-sugar  which  occurs  in  sugar-cane, 
in  beet  root,  in  sugar-maple,  etc.  But  with  the  use  of  glucose 
we  are  one  step  in  advance,  since  cane-sugar  before  fermenting 
is  first  resolved  into  a  mixture  of  dextrose  (glucose)  and  levulose. 
Commercial  glucose  is  never  pure,  as  it  contains,  besides 
about  15  percent,  of  water,  of  which  about  6  per  cent,  is  water 
of  crystallization,  about  18  per  cent,  of  dextrin  or  similar  sub- 
stances, and  some  gypsum.  It  has  a  white  color,  and  is  found 
in  commerce  packed  in  boxes  into  which  it  is  poured  while  in 
a  fluid  state  and  gradually  congeals  to  a  hard  mass.  It  is  odor- 
less and  has  a  faint  sweet  taste.  On  heating  it  becomes  smeary 
and,  finally  melts  to  a  yellowish  syrup.  Its  content  of  anhy- 
drous fruit-sugar  varies  between  62  and  67  per  cent.  Inferior 
qualities  contain  either  less  sugar,  or  have  a  more  or  less  dark 
color,  and  a  disagreeable  odor  and  taste.  Independently  of  the 
content  of  sugar,  glucose  to  be  suitable  for  the  preparation  of 
wine,  should  show  no  odor  or  by-taste. 

The  accurate  determination  of  the  content  of  pure  sugar  in 
glucose  is  connected  with  some  difficulty.  But  few  manufac- 
turers are  provided  with  the  necessary  materials  for  making 
the  analysis  with  Fehling's  solution,  and  besides  a  certain 
amount  of  skill  is  required  for  obtaining  accurate  results  by 
chemical  tests.  In  consideration  of  this,  Anthon  of  Prague 
has  devised  tables  which  are  based  upon  the  varying  specific 
gravity  of  different  saturated  solutions  of  glucose,  or  rather 


392 


MANUFACTURE    OF    VINEGAR. 


upon  its  solubility  in  water.  While  1  part  of  anhydrous  grape- 
sugar  requires  for  its  solution  1.224  parts  of  water  at  53.6  F., 
the  foreign  admixtures  accompanying  it  dissolve  in  every  pro- 
portion in  water.  Hence  a  saturated  solution  of  glucose  will 
show  a  greater  specific  gravity  the  more  foreign  substances 
it  contains.  In  Anthon's  tables  is  found  the  specific  gravity 
and  from  this  the  content  of  anhydrous  grape-sugar  or  glucose 
in  the  solution.  In  preparing  a  solution  of  starch-sugar  for 
examination  care  must  be  had  that  it  is  completely  saturated. 
Heat  must  not  be  used  for  effecting  the  solution,  but  a  certain 
quantity  of  the  glucose  to  be  examined  is  rubbed  in  a  mortar 
with  one-half  its  weight  of  water  at  53.6°  F.,  and  after  pouring 
the  thickish,  turbid  fluid  into  a  tall  beaker  it  is  allowed  to 
stand  until  clear.  Anthon's  table  is  as  follows  : — 


Specific  gravity 

Specific  gravity 

of  the  solution 

of  the  solution 

saturated  at 

Contains  of  foreign 

saturated  at 

Contains  of  foreign 

53.6°  F.  i  j 

substances. 

53.6°  F. 

substances. 

1.2066 

0  per  cent. 

1.2522 

25  per  cent. 

1.2115 

2.5     " 

1.2555 

27.5    " 

1.2169 

5.0     " 

1.2587 

30.0     " 

1.2218 

7.5 

1.2631 

32.5     " 

1.2267 

10.0 

1.2665 

35.0     " 

1.2309 

12.5 

1.2703 

37.5     " 

1.2350 

15.0 

1.2740 

40.0    " 

1.2395 

17.5 

1.2778 

42.5    " 

1.2439 

20.0 

1.2815 

45.0    " 

1.2481 

22.5 

Cider  from  Apples. — The  expressed  juice  from  well-selected 
apples,  properly  prepared,  forms  a  lively,  sparkling  liquor  far 
superior  to  many  wines.  It  is  quite  a  favorite  article  of  home 
production,  nearly  every  farmer  in  regions  where  apples  are 
grown,  making  his  barrel  of  cider  for  use  through  the  winter, 
but  a  large  amount  finds  its  way  into  the  city  markets.  -A 
considerable  quantity  is  also  consumed  in  the  shape  of  bottled 
cider,  "  champagne  cider,"  "sparkling  cider,"  and  similar 
substitutes  for,  or  imitations  of,  champagne  wines. 


MANUFACTURE    OF    CIDER.  393 

In  England  and  France  considerable  quantities  of  cider  find 
their  way  into  the  markets,  though  it  is  there,  as  here,  largely 
an  article  of  home  consumption.  Certain  parts  of  those  coun- 
tries are  famous  for  the  quality  of  their  ciders,  notably  Nor- 
mandy, in  France,  and  Herefordshire  and  Devonshire,  in 
England. 

The  Municipal  Laboratory  of  Paris  deduces  from  analyses 
of  pure  ciders  from  different  parts  of  France  the  following  as 
a  type  of  composition  for  pure  ciders  : 

Alcohol,  per  cent,  by  volume 5.66 

Extract,  per  liter,  at  212°  F.    .    . 30.00 

Ash 2.80 

Other  analyses  of  pure  ciders,  from  different  parts  of  France, 
published  by  M.  G.  Lechtartier,  have  shown  great  variations 
from  this  type,  and  show  the  necessity  for  the  examination  of 
large  numbers  of  samples  from  various  parts  of  the  country 
for  the  establishment  of  a  proper  standard  of  analysis. 

Analyses  of  Ciders  by  the  United  States  Agricultural  Depart- 
ment.— The  samples  for  the  investigation  were  purchased  in 
the  city  in  the  same  manner  as  samples  of  wine  and  beer : — 


394 


MANUFACTURE    OF    VINEGAR. 


Designation. 

Serial  No. 

^, 

"s 

"8 

6 

Specific  gravity. 

'o 

Alcohol  by  volume. 

Total  solids. 

-S 

a 
a 

£ 

X 

1 

1 

Albuminoids. 

Carbonic  acid. 

'§! 

Well-fermented  ciders. 
Draft  cider  ("  extra  dry  ")  ... 
Bottled  cider,  known  to  be 

4830 
483? 

1 
? 

1.0132 
1.0003 

p.  ct. 
4.18 

8.09 

p.ct. 
5.23 

10.05 

3.31 
1.88 

p.ct. 

.602 

.456 

p.ct. 

p.  ct. 
.396 

.279 

p.ct. 
.038 

063 

p.ct. 
trace 

0 
-19.5 

—  7.0 

Bottled  cider 

1SSS 

8 

1  0007 

628 

7  83 

180 

376 

340 

044 

6  1 

Bottled  "  extra  dry  russet  " 
cider     

4 

1.0264 

4.48 

5.61 

5.52 

.339 

393 

051 

—352 

"  Champagne  cider,"  bottled. 
"Champagne  cider,"  bottled. 
4  'Sparkling  cider,"  bottled.  . 

4835 
4836 
4927 

5 
6 

7 

1.0223 
1.5143 
1.0306 

4.08 
5.45 
3.63 

5.10 
6.79 
4.54 

5.02 
3.69 
5.92 

.567 
.361 
.113 

- 

.310 
.415 
.506 

.050 
.038 

.161 
.120 

-23.4 
—20.4 
-338 

Average                 

1  0154 

5  17 

•  6  45 

3  88 

402 

377 

044 

"Sweet"  or  incompletely 
fermented  ciders. 
Draft  cider  

1 

1.0537 

0.65 

0.81 

9.34 

.565 

.315 

.069 

—41.6 

4831 

0 

1  0516 

061 

077 

9  59 

302 

270 

063 

—  34  2 

"  Sweet  "  cider  (draft)  
Do              ..           

4837 

3 
4 

1.0567 
1  0203 

0.20 
3  46 

0.25 
4  33 

9.53 
3  84 

.575 
302 

- 

.283 
374 

.075 
044 

- 

—48.4 
—24  2 

Do       

48S9 

g 

1  0552 

0.55 

0.67 

9.75 

.409 

336 

031 

—48  5 

Do    

4841 

r, 

1  0355 

2.96 

3.71 

698 

478 

348 

069 

—391 

1  0455 

1  40 

1  76 

8  17 

405 

321 

059 

1 A  circumstance  arising  after  the  samples  had  been  thrown  away  seemed  to  throw  con- 
siderable doubt  upon  the  determinations  of  sugar,  which  were  made  by  an  assistant,  and 
the  entire  set  had  to  be  thrown  out. 

2  Determinations  of  the  carbonic  acid  in  three  different  bottles  gave  the  following  results: 
.728,  .654,  .482. 

The  choice  of  the  varieties  of  apples  is  of  great  importance 
in  the  manufacture  of  cider.  All  apple  juice  will  not  make 
equally  good  cider,  even  if  it  is  equally  well  handled.  It  is  not 
always  the  best  flavored  apple  or  the  best  tasting  juice  that  will 
make  the  best  cider.  Indeed,  as  a  rule,  the  best  cider  is  made 
from  apples  which  are  inferior  for  table  use,  such  as  the  crab- 
apple  and  the  russet.  But  it  is  a  pretty  general  rule  that  the 
most  astringent  apple  will  make  the  best  cider.  This  astrin- 


MANUFACTURE    OF    CIDER.  395 

gency  is  due  to  an  excess  of  tannin.  While  a  portion  of  this 
tannin  is  changed  to  sweetness,  a  considerable  portion  remains, 
which  serves  to  render  the  cider  more  easily  and  thoroughly 
clarified  and  to  make  it  keep  better.  The  tongue  alone  being, 
however,  not  sufficient  to  detect  the  tannin  in  apples,  the  fol- 
lowing will  serve  as  a  reliable  test:  Express  the  juice  of  a 
few  apples  and  add  a  few  drops  of  isinglass,  which  combines 
with  the  tannin  and  forms  a  precipitate.  From  the  greater 
or  smaller  quantity  of  this  precipitate  a  conclusion  can  be 
drawn  as  to  the  quantity  of  tannin  present.  The  specific 
gravity  of  the  juice,  which  may  vary  between  1.05  and  1.08 
should  be  determined.  The  greater  the  specific  gravity  of 
the  juice  the  better  the  respective  variety  of  apple  is  for 
making  cider.  According  to  these  directions,  the  raw  mate- 
rial should  be  selected,  though  in  most  cases  it  will  be 
necessary  to  use  a  mixture  of  different  varieties.  In  France, 
for  a  quality  of  cider  which  will  keep  well,  the  apples  are 
mixed  in  the  following  proportions :  f  bitter-sweet  and  J- 
sweet  apples.  If  a  sweet  cider  is  wanted  not  intended  to  be 
kept  for  a  long  while,  J  bitter-sweet  and  f  sweet  apples  are 
used. 

The  apple,  like  every  other  fruit,  consists  of  solid  and  fluid 
constituents.  The  solid  constituents  are  the  skin,  core,  seeds, 
as  well  as  the  pulp  in  the  cells  of  which  the  fluid  constituents 
— the  juice — are  enclosed.  The  solid  insoluble  constituents 
consist  chiefly  of  cellulose,  albuminous  substances,  pectose, 
mucilage  and  other  less  insoluble  substances.  The  average 
proportion  between  solid  and  insoluble  substances  and  juice  is 
of  course  subject  to  wide  fluctuations,  according  to  the  nature 
of  the  soil,  season  of  the  year  and  degree  of  ripeness. 

Generally  speaking,  the  composition  of  the  apple  may  on  an 
average  be  given  as  follows  : 

Solid  substance  (pulp)     .         .  3  to    7  per  cent. 

Juice      .  .         .         .         93  to  97  per  cent. 


396  MANUFACTURE    OF    VINEGAR. 

The  juice  constituents  contain  about : 

Water 80  to  88  per  cent. 

Sugar     .         .         .   9  to  18,  even  up  to  24  per  cent. 

Acid 0.6  to  1.8  percent. 

Extractive  substance       .         .        1.3  to     3  per  cent. 

The  juice  pressed  from  apples  is  called  must  or  cider.  The 
sugar  in  the  must  is  a  mixture  of  different  kinds  of  sugar 
varying  greatly  in  proportion,  and  consists  of  dextrose,  laevu- 
lose  and  sucrose.  The  acid  of  the  apple,  as  well  as  that  of  the 
pear,  consists  of  malic  acid,  and  frequently  also  of  small  frac- 
tions of  citric  acid ;  tartaric  acid,  however,  is  never  present. 
Must  with  less  than  5  per  cent,  of  acid  has  an  insipid  taste,  and 
consequently  an  addition  of  artificial  malic  or  citric  acid  has 
to  be  made  to  musts  augmented  with  water  in  order  to 
improve  the  taste.  On  the  other  hand,  when  the  must  con- 
tains too  much  acid,  the  latter  cannot  be  fixed  with  calcium 
or  potassium  carbonate,  but  should  be  reduced  by  the  addition 
of  water  and  sweetening  with  sugar.  The  extractive  substances 
of  apple-must  consist  of  tannin  0.2  to  0.6  per  cent.,  pectin 
bodies  4  to  4.5  per  cent.,  albuminous  substances  and  mucil- 
age, various  soluble  mineral  substances  and  a  series  of  gums 
thus  far  undetermined. 

The  apples  intended  for  the  preparation  of  cider  should  be 
allowed  to  attain  complete  maturity,  which  is  recognized  by 
their  color,  the  dark  hue  of  the  pips,  little  specks  covering  the 
skin,  and  by  the  sharp  and  agreeable  ethereal  odor  emanating 
from  them.  In  fact  they  should  be  allowed  to  remain  on  the 
trees  as  long  as  vegetation  is  active  or  until  frosts  are  appre- 
hended, for  thus  the  conversion  of  the  starch  into  sugar  is  best 
effected  and  their  keeping  better  secured  than  by  storing. 
They  should  be  gathered  by  the  hand  to  prevent  bruising  and 
coming  in  contact  with  dirt.  They  are  then  placed  in  piles  and 
allowed  to  sweat.  This  sweating  process  has  a  tendency  to  ripen 
the  fruit  and  make  it  uniform,  thereby  improving  the  flavor 
as  well  as  the  quality  and  strength  of  the  cider  in  consequence 


MANUFACTURE    OF    CIDER.  397 

of  the  apples  having  parted  with  six  or  eight  per  cent,  of  water. 
The  strongest  cider  is  made  from  apples  containing  the  smallest" 
percentage  of  juice,  and,  in  its  aqueous  solution,  the  largest 
proportion  of  saccharine  matter.  If  the  weather  be  fine,  the 
piles  may  be  exposed  in  the  open  air  upon  clean  sod  or  where 
this  is  wanting  upon  boards  or  linen  cloths,  but  under  no  cir- 
cumstances should  the  apples  be  placed  upon  the  bare  ground 
or  upon  straw,  as  they  contract  an  earthy  or  musty  taste  which 
is  afterwards  found  in  the  cider. 

After  sweating  and  before  being  ground  the  apples  should  be 
wiped  with  a  cloth  to  free  them  from  exudation  and  adhering 
particles  of  dirt,  and  if  any  are  found  bruised  or  rotten  they 
should  be  thrown  out.  Ripe,  sound  fruit  is  the  only  basis  for  a 
good  article  of  cider,  and  the  practice  of  mixing  rotten  apples 
with  the  sound,  as  is  frequently  done  and  even  advocated  by 
some,  cannot  be  too  strongly  condemned.  Mellow  or  decay- 
ing apples  have  lost  almost  all  their  perfume,  a  certain  quan- 
tity of  water  by  evaporation,  and  a  large  portion  of  their  sugar. 
Rotten  apples  yield  a  watery  liquid  of  an  abominable  taste, 
which  prevents  the  cider  from  clarifying  and  accelerates  its 
acetification. 

The  apples  being  wiped,  sorted,  and,  if  necessary,  mixed  in 
the  desired  proportions,  are  now  brought  into  the  grinder  and 
reduced  to  an  impalpable  pulp.  By  this  operation  the  numer- 
ous infinitesimal  cells  of  the  apple  should  be  thoroughly  broken 
up  so  as  to  permit  the  free  escape  of  the  juice  when  under 
pressure,  and  the  machine  which  accomplishes  this  most 
effectually  is  the  best  for  the  purpose.  If  the  cells  are  not 
thoroughly  torn  asunder,  their  tendency  is  to  restrain  and 
hold,  as  it  were,  in  a  sack  much  that  otherwise  would  escape. 
As  regards  the  crushing  of  the  seeds  there  is  a  diversity  of 
opinion,  some  holding  that  they  communicate  to  the  cider  a 
disagreeable  bitterness  and  acidity,  while  others  consider  them 
as  rendering  the  cider  more  alcoholic  and  making  it  keep 
better. 

According  to  M.  Bergot,  for  cider  of  superior  quality  it  is 


398  MANUFACTURE    OF    VINEGAR. 

preferable  not  to  crush  the  seeds,  because  the  diffused  odor  of 
the  essential  oil  would  undoubtedly  injure  the  fine  taste  of  cer- 
tain notable  products.  For  ordinary  cider  the  crushing  of  the 
seeds  will,  on  the  other  hand,  be  of  advantage,  because  their 
essential  oil  helps  to  give  to  the  cider  the  bouquet  which  it 
otherwise  lacks.  For  cider  intended  to  be  converted  into 
brandy  the  seeds  must,  however,  be  crushed.  The  grinder 
should  be  cleansed  with  hot  water  every  evening,  or  at  least 
every  third'  day. 

The  treatment  to  which  the  pulp  obtained  by  grinding  is 
subjected  varies  according  to  the  color  the  cider  is  to  have. 
Where  the  consumer  prefers  a  pale-yellow  color  the  pulp  must 
at  once  be  pressed,  while  for  a  darker  color  it  is  allowed  to 
stand  12  to  18  hours. 

The  next  step  in  the  operation  is  pressing.  The  various  kinds 
of  presses,  racks,  and  manner  of  laying  up  the  cheese  have 
already  been  described.  The  primitive  custom  of  laying  the 
cheese  was  to  lay  upon  the  platform  of -the  press  a  quantity  of 
straw,  upon  which  a  quantity  of  pomace  was  placed,  and  the 
edges  secured  by  laps  of  straw,  thus  alternating  straw  and 
pomace  until  the  pile  was  complete.  The  object  of  using  the 
straw  was  to  hold  the  mass  together  while  it  was  being  sub- 
mitted to  pressure,  and  also  to  serve  as  a  means  of  exit  for  the 
cider.  An  improvement  was  in  the  substitution  of  hair-cloths, 
and  within  the  past  few  years  the  adoption  of  the  cotton  press- 
cloth  and  racks  to  hold  the  pomace  in  laying  up  the  cheese 
for  the  press.  The  racks  have  already  been  described.  The 
press-cloth  is  woven  from  yarn  made  expressly  for  the  purpose 
and  is  of  equal  strength  in  warp  and  filling.  The  use  of  straw 
in  laying  up  the  cheese  should  be  entirely  discarded,  as  the 
slightest  mustiness  imparts  an  unpleasant  odor^to  the  cider. 

The  pressure  applied  to  the  cheese  should  be  slow  at  starting 
and  then  gradually  increased  until  finally  the  full  force  is 
applied.  The  juice  as  it  comes  from  the  press  runs  through  a 
fine  hair-sieve  into  a  receiver.  With  a  good  press  about  65  to 
75  per  cent,  of  juice  will  be  obtained. 


MANUFACTURE    OF    CIDER.  399 

After  the  cider  has  been  extracted  and  the  cheese  removed 
from  the  press  the  pomace  may  be  utilized  for  the  manufacture 
of  vinegar,  as  previously  described.  In  France  it  is,  however, 
used  for  the  manufacture  of  the  small  cider.  The  method  is  as 
follows: — After  the  extraction  of  the  pure  cider  by  the  first 
pressing,  the  pomace  is  taken  from  the  press,  and  after  adding 
12  litres  of  water  for  every  hectoliter  of  apples  used,  the  mass 
is  allowed  to  macerate  15  to  20  hours,  care  being  had  to  stir 
every  two  or  three  hours.  Then  this  pulp  is  put  a  second  time 
under  pressure  and  a  quantity  of  juice  extracted  equivalent  to 
the  amount  of  water  added. 

Extraction  of  the  juice  by  diffusion. — Diffusion,  which  gives 
such  excellent  results  in  the  extraction  of  sugar-beets,  has  also 
been  applied  to  extract  the  soluble  constituents  of  the  apple. 
In  practice  this  method  might  be  suitable  for  persons  having 
no  cider  press  and  only  a  small  quantity  of  apples  to  handle. 
The  quality  of  cider  is  nearly  equal  to  that  obtained  by  three 
pressures,  and  the  juice  obtained  is  almost  as  rich  as  that 
yielded  by  the  press. 

Successful  experiments  in  expressing  the  juice  of  the  grape 
by  means  of  the  centrifugal  would  indicate  that  the  same 
method  might  also  be  applied  to  apples. 

.  The  freshly-expressed  apple-juice  is  either  sold  as  sweet 
cider  or  subjected  to  fermentation.  Fermentation  in  sweet 
cider  is  retarded  by  pasteurizing,  carbonating,  or  the  addition 
of  preservatives.  The  objections  urged  against  pasteurizing 
or  sterilizing  fresh  apple-juice  are  that  a  "cooked  "  taste  is 
added  to  the  juice,  and  that  it  is  impracticable  to  hold  the 
juice  sterile  for  more  than  a  limited  period.  Experiments  to 
develop  a  method  for  sterilizing  apple-juice  in  wooden,  tin  and 
glass  containers  have  been  made  by  H.  C.  Gore,*  and  his 
investigations  demonstrate  that  only  a  slight  cooked  taste  is 
produced  by  the  heat  treatment  required,  and  that  it  is  a  sim- 

*  U.  S.  Department  of  Agriculture,  Bureau  of  Chemistry,  Bulletin  No.  118. 
"  Unfermented  Apple-juice." 


400  MANUFACTURE    OF    VINEGAR. 

pie  matter  to  protect  the  juice  from  inoculation  after  steriliz- 
ing.    A  summary  of  these  investigations  is  here  given  : — 

(1)  "  The  experiments  show  conclusively  that  it  is  possible 
to  sterilize  apple-juice  in  wooden  containers,  the  product  re- 
maining sound  for  at  least  six  months  under  actual  observa- 
tion.    The  precautions  which  must  be  taken  to  insure  this  are 
as  follows :  First  paraffin  the  containers  on  the  outside,  then 
sterilize,  and  fill  with  juices  heated  to  between  149°  and  158° 
F.  (65°  to  70°  C.) ;  seal,  taking  measures  to  relieve  the  vacuum 
produced  by  the  contraction  of  the  juice  on  cooling  by  filter- 
ing the  air  through  cotton.     Twenty-four  10-gallon  kegs  suc- 
cessfully stood  a  severe  shipping  test,  showing  no  loss  due  to 
fermentation  of  the  juice.     The  juice  so  prepared  was  found 
to  be  palatable,  and  acceptable  as  a  summer  drink. 

(2)  "  It  is  demonstrated  that  apple-juice  can  be  successfully 
sterilized  in  tin  containers,  using  the  type  of  tin  can  sealed  by 
the  mechanical   process,   excluding  all   metals  from  contact 
with  the  juice  except  the  tin  of  the  can.     Where  lacquered 
cans  are  used  the  contamination  with  tin  was  reduced  about 
one-half.     Apple  juices  were  canned  and  sterilized  by  heating 
in  a  hot  water-bath,  up  to  the  temperature  of  149°  F.  (65°  C.) 
for  a  half  hour,  and  then  allowed  to  cool.     These  juices  pos- 
sessed only  a  slight  cooked  taste  due  to  the  heating  and  re- 
tained much  of  their  distinctive  apple  flavor.     It  was  found 
that  from  finely  flavored  apple-juice  a  first-class  sterile  product 
could  be  made,  while  a  poorly  flavored  apple-juice  yielded  an 
inferior  product.     The  process  conditions  mentioned  were  not 
quite  thorough  enough  to  sterilize  all  of  the  varieties  canned. 
A  slight  increase  in  the  temperature  or  time  of  processing,  or 
both,  should  be  made,  the  temperature  not  to  exceed  70°  C. 
(158°  F.)  in  any  case. 

(3)  "  The  best  treatment  for  sterilizing  in  glass  was  found 
to  consist  in  heating  for  one  hour  at  149°  F.,  or  for  one-half 
hour  at  158°  F.     Heating  for  one  hour  at  158°  did  not  pro- 
duce marked  deterioration  in  flavor,  a  half  hour  being  allowed 
in  all  cases  for  the  juice  to  obtain  the  temperature  of  the 
water-bath. 


MANUFACTURE    OF    CIDER.  401 

(4)  "  It  was  shown  that  the  great  bulk  of  the  insoluble 
material  naturally  contained  in  apple-juice  can  be  removed 
by  means  of  a  milk  separator." 

These  investigations  extended  also  to  carbonating  fresh 
apple-juice  and  the  conclusions  arrived  at  are  as  follows: 

"  It  is  possible  to  carbonate  the  juice  slightly  before  canning 
or  bottling,  thus  adding  a  sparkle  to  the  product.  A  flavor 
foreign  to  fresh  apple-juice  is  also  added,  however,  and  un- 
carbonated  sterile  juice  will  resemble  fresh  apple-juice  more 
closely.  Carbonating  by  the  addition  of  water  charged  with 
carbon  dioxid  was  considered  by  some  to  injure  the  flavor, 
lessening  the  characteristic  fruit  flavor  by  dilution.  In  the 
opinion  of  others  a  heavy,  rich  juice  was  improved  both  by 
the  charge  of  carbon  dioxid  and  by  the  consequent  dilution. 
Experiments  indicated  that  the  danger  of  contamination  by 
mold  growths  was  lessened  by  maintaining  an  atmosphere  of 
carbon  dioxid  above  the  surface  of  the  juice  after  opening." 

When  apple-juice  is  sold  in  bulk  a  small  amount  of  benzo- 
ate  of  soda  is,  as  a  rule,  added  to  retard  fermentation,  one- 
tenth  of  1  per  cent,  being  tolerated  by  regulation  in  the  United 
States.  H.  C.  Gore's  investigations  demonstrated  that  benzo- 
ate  of  soda  in  quantities  varying  from  0.03  to  0.15  per  cent., 
while  it  checks  the  alcoholic  fermentation,  allows  other  organ- 
isms to  develop — notably  the  acetic  acid  ferment — whereby 
the  palatability  of  the  product  as  a  beverage  is  destroyed. 

H.  C.  Gore  has  also  investigated  the  cold  storage  of  apple 
cider,*  and  the  summary  of  the  results  of  these  investigations 
is  here  given  : 

(1)  "  Ciders  prepared  from  apples  free  from  decay  chilled 
rapidly  to  the  freezing-point  immediately  after  pressing,  and 
then  held  in  cold  storage  at  0°  C.  (32°  F.)  remained  without 
noticeable  fermentation  for  a  period  of  from  thirty-six  to  fifty- 
seven  days,  an  average  of  fifty  days  for  the  Tolrnan,  Winesap, 

*  U.  S.  Department  of  Agriculture,  Bureau  of  Chemistry,   Circular  No.  48, 
"The  Cold-Storage  Apple  Cider." 
26 


402  MANUFACTURE  OF  VINEGAR. 

Yellow  Newtown,  Rails,  Gilpin,  and  Baldwin  varieties,  and  of 
eighty-three  days  in  the  case  of  the  Golden  Russet,  Roxbury 
Russet,  and  Kentucky  Red. 

(2)  "  These  ciders  were  held  for  a  period  of  from  ninety  to 
one  hundred   and   nineteen  days,  an  average  of  ninety-nine 
days  for  the  first  six  varieties  and  of  one  hundred  and  twenty- 
five  days  for  the  last  three,  before  they  fermented  sufficiently 
to  be  considered  as  becoming  "  hard  "  or  "  sour." 

(3)  "  The  ciders  were  found  to  have  suffered  no  deteriora- 
tion (with  the  exception  of  the  Tolman),  but  rather  had  be- 
come more  palatable  during  storage." 

The  apple-juice  to  be  fermented  should  be  tested  with  a 
must-spindle  or  densimeter  as  to  its  content  of  sugar.  A  good 
quality  of  juice  will  generally  range  from  10  to  14  per  cent. 
If  less  than  10  per  cent,  the  juice  will  not  make  a  cider  that 
will  keep,  though,  if  the  flavor  in  other  respects  is  all  right,  a 
beverage  for  immediate  use  may  be  produced  from  it. 

When  the  juice  has  been  tested  and,  if  found  wanting  in 
saccharine  strength,  corrected  by  the  method  previously  given, 
the  next  step  in  the  operation  is  fermentation.  For  this  pur- 
pose the  juice  is  brought  into  casks.  Regarding  the  size  of 
the  latter  it  may  be  said  that,  as  a  rule,  the  juice  ferments 
more  uniformly  and  more  steadily,  and  retains  the  carbonic 
acid  better  with  the  use  of  larger  casks,  though  it  develops 
somewhat  more  slowly  than  in  smaller  containers.  For  the 
production  on  a  large  scale  of  cider  of  first-rate  quality  the 
use  of  large  casks  can,  therefore,  be  recommended.  However, 
if  the  cider  is  to  be  used  for  daily  consumption,  and  perhaps 
be  directly  drawn  from  the  yeast,  smaller  containers  are  pre- 
ferable, there  being  less  danger  of  the  cider  becoming  mouldy 
or  sour.  The  casks  should  be  scrupulously  clean,  and  new 
ones  must  be  freed  by  steaming  or  washing  with  hot  water 
from  all  extractive  substances,  otherwise  the  cider  will  acquire 
a  disagreeable  taste  and  dark  color. 

In  many  places  the  fermentation-casks  are  filled  by  means 
of  a  power  pump  which  delivers  the  juice  to  the  receptacles 


MANUFACTURE    OF    CIDER.  403 

placed  in  adjacent  rooms  or  in  another  building.  When  the 
press-room  is  over  the  fermentation  room,  filling  is  accom- 
plished by  gravity.  Hose-pipes  are  largely  used  for  this  work, 
but  brass  or  copper  must  be  used  for  all  metal  fittings.  The 
less  the  juice  comes  in  contact  with  the  air  after  it  leaves  the 
press  the  less  liable  it  is  to  be  contaminated  with  various  un- 
desirable organisms.  The  pumps  and  pipes  must  be  kept 
scrupulously  clean. 

In  Fig.  97  p.  386  the  juice  running  off  from  the  press 
through  the  pipe  H  is  freed  from  the  principal  particles  of 
pulp  in  the  box  J,  which  is  fitted  with  two  or  three  wire- 
sieves  of  different  fineness.  This  box  is  located  above  the 
collecting  vat  K. 

The  fresh  juice  having  been  brought  into  the  casks,  fermen- 
tation is  still  left  in  many  places  to  the  organisms  normally 
present  on  the  fruit  and  those  which  may  at  the  time  of  grind- 
ing and  pressing  enter  the  juice  from  contact  with  the  air,  the 
machinery  and  the  vessels.  Fermentation  in  this  case  does 
not  always  progress  as  norn^lly  and  favorably  as  required 
for  the  production  of  a  sound,  palatable  and  durable  cider. 
The  various  races  of  yeast  present  on  the  apple  possess  but 
little  fermenting  power  and  the  elliptic  wine  yeast  (sacchar- 
omyces  ellipsoidus)  which  has  to  be  taken  chiefly  into  account, 
being  generally  represented  only  in  very  small  quantities,  is 
stifled  and  readily  suppressed.  It  is  a  well-known  fact  that, 
generally  speaking,  apple  juice  ferments  completely  only  with 
difficulty.  This  appears  to  be  due  to  the  fact  that  the  nat- 
ural cane  sugar,  which  is  frequently  present  in  considerable 
quantities  in  apple  and  pear  juices,  is  fermented  with  great 
difficulty  by  the  organism  normally  present  on  the  fruit,  and 
to  assure  the  ascendancy  of  the  true  yeasts  and  thus  give  them 
the  control  of  the  entire  process  of  fermentation,  the  practice 
of  sowing  the  juices  with  pure  cultures  of  yeast  has  been  intro- 
duced. In  Germany  all  the  important  factories  employ  these 
cultures,  which  are  obtained  in  small  flasks  from  the  Royal 
Pomological  School  at  Geisenheim.  With  the  use  of  pure 


404  MANUFACTURE  OF  VINEGAR. 

,  culture  of  yeast  it  is  best  to  add  it  to  a  smaller  quantity  of 
sterile  juice  previously  heated  to  140°  F.  and  then  cooled  to 
68°  F.  When  fermentation  in  the  sterile  fluid  is  most  vig- 
orously developed  i't  is  added  to  the  juice  to  be  fermented. 

Another  cause  of  the  difficult  fermentation  of  apple  juice  is 
the  frequent  want  of  nitrogenous  combinations  required  for 
the  nutriment  and  propagation  of  the  yeast.  This  may  be 
remedied  by  the  addition  of  20  grammes  of  ammonium  tar- 
trate  or  ammonium  chloride  per  hectoliter  of  juice ;  in  place 
of  it  the  same  quantity  by  weight  of  ammonium  phosphate  or 
ammonium  carbonate  may  also  be  used.  Such  an  addition 
should  also  be  made  with  the  use  of  pure  culture  of  yeast. 

The  first  or  tumultuous  fermentation  of  the  apple  juice  is  in 
some  places  effected  in  open  vats,  this  method  being  generally 
preferred  with  juice  not  previously  strained,  so  as  to  be  able 
to  remove  during  fermentation  the  insoluble  constituents  of 
the  must  which  are  forced  to  the  surface. 

When,  however,  the  must  has  been  purified  by  straining  or 
filtering  over  thoroughly  washed  sand,  fermenting  in  casks  is 
preferable.  The  casks  are  fillea  about  three-quarters  full  and 
equipped  with  a  ventilating  bung  to  prevent  the  entrance  of 
germ-laden  air.  There  are  various  constructions  of  ventilating 
bungs  but  the  principle  is  in  all  cases  the  same,  namely,  to 
allow  the  escape  of  the  excess  of  carbonic  acid  and  prevent  the 
entrance  of  air.  The  best  protection  of  the  must  is  the  car- 
bonic acid  developed  during  fermentation,  because,  on  the  one 
hand,  neither  mould  or  acetic  acid  formation  can  appear  for 
want  of  oxygen,  and,  on  the  other,  the  exciters  of  these  decom- 
positions cannot  develop  in  an  atmosphere  of  carbonic  acid. 
Care  should,  therefore,  be  taken  that  until  fermentation  is  fin- 
ished and  the  cask  has  been  entirely  filled  and  bunged,  an 
atmosphere  of  carbonic  acid  always  lies  over  the  cider  in  the 
empty  space  of  the  cask. 

The  fermentation  funnel  or  ventilating  funnel,  Fig.  98  which 
is  largely  used  in  Germany,  is  a  simple  device  for  controlling 
the  air.  It  is  generally  made  of  pottery  or  porcelain,  though 


MANUFACTURE    OF    CIDER.  405 

it  can  also  be  constructed  of  metal,  for  instance,  aluminium. 
It  consists  of  two  parts,  the  actual  funnel  c  with  the  tapering 
pipe  d,  which  is  secured  air-tight  in  the  bung-hole  and  is  filled 
half-full  with  water,  and  a  cup-like  vessel  b,  which  is  placed 
over  the  elongated  portion  of  the  pipe  of  the  funnel.  The 
carbonic  acid  escaping  from  the  cask  passes  through  the  pipe 
into  the  cup  b,  forces  back  the  water  at  o  and  escapes  at  e  from 
the  open  portion  of  the  funnel,  the  entrance  of  air  being  on 
the  other  hand  prevented  by  the  water. 

The  first  or  tumultuous  fermentation  runs  its  course,  accor- 
ing  to  temperature  and  other  conditions,  in  two  to  four  weeks, 


the  temperature  being  under  otherwise,  normal  conditions,  the 
most  important  factor.  The  higher  it  is  ,  the  more  energetic- 
ally fermentation  sets  in  and  the  more  rapidly  it  runs  its 
course.  While  formerly  a  not  too  tumultuous  course  of  the 
first  fermentation  was  not  desired  by  many  manufacturers  and 
the  temperature  was  kept  relatively  low,  most  of  them  have 
now  arrived  at  the  conclusion  that  as  energetic  a  course  as 
possible  of  the  first  fermentation  is  the  best  guarantee  for  a 
good  product,  and  the  temperature  for  the  first  stage  of  fer- 
mentation should  be  at  least  between  59°  and  68°  F.  When 
the  first  fermentation  has  run  its  course,  which  is  recognized 
by  the  cessation  of  the  hissing  sound  made  by  the  carbonic 


406  MANUFACTURE    OF    VINEGAR. 

acid  gas,  the  cider  is  drawn  off  from  the  sediment  into  clean, 
unsulphured  casks,  furnished  with  a  ventilating  bung.  The 
casks  are  placed  in  a  cellar  or  a  cool  room  having  a  tempera- 
ture of  40°  to  50°  F.,  and  the  cider  is  left  to  the  second  or  after 
fermentation.  The  casks  should  be  constantly  kept  full,  and 
abrupt  variations  in  the  temperature  carefully  avoided  and 
provided  against.  Generally  speaking,  the  more  energetically 
the  first  fermentation  has  run  its  course,  the  more  quietly  the 
second  fermentation  will  progress,  and  vice  versa.  By  the 
second  fermentation,  the  remainder  of  the  sugar  is  decomposed, 
there  is  but  a  slight  evolution  of  carbonic  acid,  the  yeast  as 
as  well  as  the  albuminous  substances  in  the  must  settle  on 
the  bottom,  and  the  cider  becomes  more  or  less  clear. 

When  the  second  fermentation  has  progressed  to  the  desired 
degree,  the  cider  is  drawn  off  into  other  casks  and  fined.  Ac- 
cording to  one  method  this  is  done  with  isinglass,  1J  ozs.  of  it 
being  allowed  for  each  cask.  This  quantity  is  dissolved  in  1 
pint  of  cider  over  a  moderate  fire,  and  the  solution  when 
cold,  poured  with  constant  agitation  into  the  cask.  Drawing 
off  may  be  commenced  after  eight  days. 

A  better  method  of  clarification,  which  at  the  same  time  in- 
creases the  purity  of  taste  of  the  cider,  is  as  follows  :  For  each 
barrel  of  30  gallons,  take  4  Ibs.  of  fresh  wheat  bran,  and,  after 
washing  it  twice  in  hot  water  to  remove  all  soluble  substances, 
press  out  thoroughly.  Now  dissolve  about  2  drachms  of  alum 
in  a  bucketful  of  hot  water  and.  pour  the  solution  upon  the 
bran.  After  6  to  8  hours  take  the  latter  from  the  alum  water 
and  press  as  before.  The  bran  is  best  used  before  the  cider  is 
racked  off  for  the  third  and  last  time.  Stir  it  into  the  cider, 
and  then  draw  off  the  latter  through  a  fine  strainer  into  the 
actual  storage  barrel.  The  cider  first  passing  through  the 
strainer  is  generally  somewhat  turbid,  and  must  be  poured 
back  until  it  runs  off  clear. 

In  France,  the  cider  is  generally  clarified  by  dissolving  2  ozs. 
of  catechu  in  1  quart  of  cider  and  adding  the  solution  to  100 
quarts  of  cider,  with  constant  stirring.  The  tannin  thus  added 


MANUFACTURE    OF    CIDER.  407 

precipitates  the  albuminous  matters,  the  result  being  a  clear 
cider  which  will  not  blacken  in  the  air. 

It  is  always  advisable  before  fining  large  quantities  of  cider 
to  make  a  clarifying  experiment  on  a  small  scale,  the  content 
of  tannin  in  the  fluid  being  frequently  so  small  that  the  clari- 
fying agent  added  is  ineffectual.  In  such  cases  a  small  addi- 
tion of  tannin  in  the  form  of  an  alcoholic-aqueous  solution 
previous  to  the  addition  of  the  clarifying  agent  can  be  recom- 
mended. However,  as  a  perfectly  bright  product  is  not  always 
obtained  by  fining,  filtering  will  ha^  to  be  resorted  to.  Fil- 
ters of  various  types,  such  as  bag  filters,  cellulose  filters  and 
asbestos  filters  are  in  use  for  this  purpose.  Filtering  cider 
appears  to  be  a  process  much  more  difficult  than  filtering  wine 
made  from  grapes  and  should  be  avoided  if  possible.  The 
reason  for  this  is  the  presence  of  mucilaginous  substances  in 
the  liquor. 

Pared  apples,  if  used  for  the  production  of  cider,  yield  a 
product  poor  in  aroma.  Washing  the  apples  in  washing 
machines  of  special  construction  previous  to  grinding  and 
pressing  is  of  great  advantage  for  the  production  of  fine  must 
and  cider.  Fairly  good  products  can  be  obtained  from  dried 
American  apples,  the  cheapest  brands  (waste,  parings,  cores) 
of  which  can  be  used  for  the  purpose. 

Cider  intended  for  export  must  be  made  somewhat  richer 
in  alcohol,  which  is  generally  done  by  adding  sufficient 
French  brandy  to  increase  its  content  of  alcohol  2  per  cent. 
Sometimes,  also,  J  Ib.  of  sugar  for  every  2  quarts  of  juice  is 
added  during  fermentation.  For  shipping  to  tropical  countries 
experiments  might  be  made  with  salicylic  acid,  adding  it  in 
the  same  proportion  as  to  beer,  which  is  for  beer  sent  in 
barrels  f  oz.  for  100  quarts,  and  for  bottled  beer,  J  oz. 

There  are  several  methods  of  improving  the  taste  of  cider, 
but  they  are  rather  questionable,  because  tastes  differ,  and 
what  might  be  considered  an  improvement  by  one  would  be 
declared  a  defect  by  another.  A  favorite  method  of  improve- 
ment is  as  follows  :  For  45  gallons  of  cider  measure  off  3  quarts 


408  MANUFACTURE  OF  VINEGAR. 

of  French  brandy  and  mix  it  with  the  following  substances? 
all  finely  powdered  :  0.7  drachm  of  bitter  almonds,  0.7  drachm 
of  mace,  and  7J  drachms  of  mustard-seed,  and  finally  3J 
drachms  of  catechu,  previously  dissolved  in  water.  Pour  this 
mixture  into  the  cider  and  shake  the  barrel  frequently  during 
the  next  14  days.  Then  allow  it  to  rest  three  or  four  months, 
and  should  it  then  not  run  off  clear  when  tapped,  clarify  it 
with  1 J  oz.  of  isinglass  or  the  whites  of  a  dozen  eggs.  If  the 
color  of  the  cider  is  to  remain  pale  yellow,  catechu  cannot  be 
used,  and  instead  of  isinglass  or  white  of  egg,  skimmed  milk 
is  to  be  used  for  clarification.  For  a  reddish  color,  which  is 
sometimes  desired,  use  If  drachms  of  powdered  cochineal  in 
place  of  the  catechu. 

Sometimes  cider  is  prepared  in  the  same  manner  as  other 
fruit-wines.  In  this  case  J  Ib.  of  sugar  is  added  to  every  quart 
of  juice,  and  the  latter  is  allowed  to  completely  ferment  in  the 
same  manner  as  grape  wine.  According  to  another  direction, 
add  to  every  2  quarts  of  juice,  2  Ibs.  of  white  sugar,  and  boil 
as  long  as  scum  is  formed  ;  then  strain  through  a  fine  hair- 
sieve  and  allow  to  cool.  Now  add  a  small  quantity  of  yeast, 
stir  thoroughly,  let  the  whole  ferment  three  weeks,  and  after 
clarifying  rack  off  into  bottles. 

Red  apple  wine,  or,  as  it  is  frequently  called,  red  wine  from 
cider,  is  prepared  as  follows  :  Boil  for  2  hours  50  quarts  of 
apple  juice,  27  Ibs.  of  honey,  1  oz.  of  tartar,  6  Ibs.  of  comminuted 
red  beets,  and  3, Ibs.  of  brown  sugar.  Let  the  fluid  completely 
ferment,  and  if  no  apple  juice  is  on  hand  to  fill  up  the  barrel 
during  this  process,  use  solution  of  sugar.  When  fermentation 
is  finished,  pour  a  mixture  of  1  quart  of  French  brandy  and 
about  1  drachm  each  of  pulverized  cinnamon  and  ginger  into 
the  barrel.  After  three  months  clarify  the  wine  and  rack  off. 

In  his  treatise  on  "  Cider,"  Dr.  Denis-Dumont  gives  the  fol- 
lowing directions  for  bottling  cider  :  The  cider  is  to  be  bottled 
at  three  distinct  periods.  It  should  never  be  bottled  before 
the  tumultuous  stage  of  fermentation  is  entirely  completed  and 
the  liquid  clarified. 


MANUFACTURE    OF    CIDER.  409 

First  period.  At  the  termination  of  the  tumultuous  fermen- 
tation, the  cider  still  contains  considerable  sugar.  Fermen- 
tation continues  in  the  bottle  and  produces  in  a  few  weeks  a 
large  quantity  of  carbonic  acid.  In  order  to  prevent  the  bottles 
from  being  broken  by  the  pressure,  champagne  bottles  should 
be  selected,  and  care  taken  to  have  them  stand  upright  until 
the  development  is  considerably  reduced.  The  bottles  are 
then  laid  on  their  side,  as  otherwise  the  cider  would  cease  to 
be  sparkling.  This  cider  has  to  be  kept  for  a  number  of  years, 
it  being  good  to  drink  only  when  old. 

Second  period,  when  fermentation  is  more  advanced,  about 
six  weeks  or  two  months  after  the  first  period.  Mineral  water 
bottles  are  strong  enough  to  hold  this  cider,  it  liberating  less 
carbonic  acid  than  the  preceding.  The  bottles  are  left  in  an 
upright  position  for  a  few  weeks  only.  This  cider  has  a  good 
flavor  and  is  fit  to  drink  much  sooner  than  the  preceding.  It 
keeps  for  a  long  time. 

Third  period,  when  fermentation  is  complete  or  almost  so, 
any  quality  of  bottles  may  be  used,  a  great  deal  less  of  car- 
bonic acid  being  developed  than  in  the  preceding  cases.  The 
bottles  should  be  laid  down  immediately  after  filling,  in  order 
to  retain  the  carbonic  acid  which  will  still  be  developed.  This 
cider  is  not  sparkling ;  it  is,  however,  lively,  strong,  and  has  a 
fine  flavor. 

The  bottles  should,  in  every  instance,  be  well  corked,  and 
the  corks,  for  the  sake  of  safety,  tied.  The  cider  is  very  good 
when  kept  in  small  bottles,  better  in  quart  bottles,  and  best  in 
jars  holding  two  quarts.  A  few  moments  before  opening  a 
bottle  of  sparkling  cider,  it  is  advisable  to  provide  a  minute 
opening  for  the  escape  of  the  gas  by  piercing  the  cork  with  a 
fine  punch.  As  soon  as  the  tension  of  the  gas  has  become 
sufficiently  weak,  the  cork  is  allowed  to  blow  out  in  the  same 
manner  as  with  champagne.  Without  this  precaution,  most 
of  the  cider  might  be  thrown  up  to  the  ceiling. 

In  the  island  of  Jersey,  where  the  manufacture  of  cider  is 
carried  on  in  a  very  rational  manner,  the  juice  as  it  comes  from 


410  MANUFACTURE    OF    VINEGAR. 

the  press  is  allowed  to  ferment  in  large  open  vats  placed  in  a 
cellar  having  a  uniform  temperature  of  from  53°  to  59°  F.  On 
account  of  the  large  surface  presented  to  the  air,  tumultuous 
fermentation  soon  sets  in,  and  in  about  four  or  five  days,  or  at 
the  utmost  a  week,  fermentation  is  over.  The  liquid  is  then 
drawn  off  in  barrels,  thoroughly  cleansed  and  sulphured,  in 
which  fermentation  continues  slowly.  These  barrels  are  not 
entirely  filled,  and  when  the  development  of  carbonic  gas  has 
proceeded  so  far  that  the  flame  of  a  lighted  candle  introduced 
by  the  bung-hole  is  extinguished,  the  liquid  is  drawn  off  into 
other  barrels  sulphured  like  the  first.  This  transfer  from  one 
set  of  barrels  to  another  is  continued  until  no  escape  of  gas  is 
perceptible,  i.  e.,  until  fermentation  is  quite  complete. 

Prepared  in  this  manner  the  cider  will  keep  perfectly  good 
for  several  years,  and  stand  transportation  by  sea  without  any 
difficulty. 

Devonshire  cider  is  made  from  a  mixture  of  one-third  of 
bitter-sweet  apples  with  a  mild  sour.  These  being  gathered 
when  thoroughly  ripe  are  allowed  to  undergo  the  sweating  pro- 
cess before  grinding.  The  cider  is  then  pressed  in  the  usual 
manner  and  strained  through  a  hair-sieve  into  hogsheads, 
where  it  remains  for  two  or  three  days  previous  to  fermenting. 
It  is  then  drawn  off  into  clean  casks  to  stop  the  fermentation, 
but  if  this  is  very  strong  only  two  or  three  gallons  are  first  put 
in,  and  after  burning  cotton  or  linen  rags  saturated  with  sul- 
phur in  the  cask,  thoroughly  agitated.  This  completely  stops 
fermentation  in  that  quantity  and  usually  checks  it  in  the  other 
portion  with  which  the  cask  is  then  filled  up.  In  a  few  weeks 
the  cider  becomes  very  fine.  If  this  be  not  satisfactorily  ac- 
complished by  the  first  operation,  it  is  repeated  until  fermen- 
tation is  completely  checked  and  the  cider  is  in  a  quiet  state 
and  in  a  proper  condition  for  drinking  and  bottling. 

Champagne-cider. — The  manufacture  of  this  beverage  has 
become  quite  important — it  resembling  the  ordinary  but  more 
expensive  champagne-wine,  and  being  frequently  sold  as  such. 
Since  the  devastation  of  the  vineyards  by  the  phylloxera,  a 


MANUFACTURE    OF    CIDER.  411 

large  trade  in  the  spurious  champagne-wine  is  carried  on  in 
France.  This  champagne-cider  if  sold  under  its  right  name 
is  an  excellent  beverage.  It  is  prepared  as  follows :  To  50 
gallons  of  apple-juice  add  12  quarts  of  brandy  and  14  Ibs.  of 
sugar  or  honey.  Mix  the  whole  thoroughly,  and  allow  it  to 
ferment  for  one  month  in  a  cool  place.  Then  add  about  4 
drachms  of  orange-blossom  water,  and  clarify  with  2  quarts 
of  skimmed  milk.  The  champagne  is  now  ready  and  is  racked 
off  into  bottles,  into  each  of  which  a  small  piece  of  white  sugar 
is  thrown,  and  the  corks  of  which  are  wired.  The  duration 
of  fermentation  has  been  stated  as  one  month.  It  may,  how- 
ever, last  a  few  days  more  or  less,  it  being  entirely  a  matter  of 
observation  when  the  most  suitable  time  for  racking  off  has 
arrived.  No  more  rising  of  bubbles  of  gas  should  be  observed, 
but  fermentation  must  not  be  completely  finished. 

According  to  another  process,  40  quarts  of  fermented  apple- 
juice  are  mixed  with  2  quarts  of  solution  of  sugar,  J  quart  of 
rectified  alcohol  and  2  ozs.  and  4  drachms  of  pulverized  tar- 
tar. The  mixture  is  allowed  to  stand  24  hours  and  then 
racked  off  into  bottles,  each  bottle  receiving  a  drachm  of  bicar- 
bonate of  soda.  Cork  and  wire. 

Another  process  consists  in  bringing  into  a  vat  40  quarts  of 
apple-juice,  5  Ibs.  of  white  sugar,  J  Ib.  of  tartar,  1  pint  of  rec- 
tified alcohol,  j-  pint  of  yeast  and  1  oz.  and  2J  drachms  of 
acetic  ether.  Shortly  before  fermentation  is  finished  the  mix- 
ture is  drawn  off  into  bottles,  each  of  which  has  previously 
been  provided  with  a  small  piece  of  sugar.  Clarification  with 
isinglass,  white  of  egg  or  skimmed  milk  must,  of  course,  pre- 
cede the  drawing  off  into  bottles.  The  bottles  must  be  thor- 
oughly corked  and  wired  in  the  same  manner  as  genuine 
champagne,  and  laid  in  a  cool  cellar. 

Cider  serves  frequently  as  a  basis  for  artificial  wines,  genuine 
Burgundy,  sherry  or  port-wine,  prepared  from  cider  mixed 
with  suitable  substances,  being  frequently  served  even  in  first- 
class  hotels.  Nothing  could  be  said  against  these  beverages  if 
they  were  sold  under  their  proper  names,  because  they  consist 


412  MANUFACTURE    OF    VINEGAR. 

of  harmless  substances,  which  cannot  always  be  said  of  the 
genuine  wines,  they  being  only  too  frequently  adulterated  with 
substances  injurious  to  health. 

Burgundy. — Bring  into  a  barrel  40  quarts  of  apple  juice,  5 
Ibs.  of  bruised  raisins,  £  Ib.  of  tartar,  1  quart  of  bilberry  juice 
and  3  Ibs.  of  sugar.  Allow  the  whole  to  ferment,  filling  con- 
stantly up  with  cider.  Then  clarify  with  isinglass,  add  about 
1  oz.  of  essence  of  bitter  almonds,  and  after  a  few  weeks  draw 
off  into  bottles. 

Malaga  Wine. — Apple  juice,  40  quarts  ;  crushed  raisins,  10 
Ibs.;  rectified  alcohol,  2  quarts;  sugar  solution,  2  quarts; 
elderberry  flowers,  1  quart;  acetic  ether,  1  oz.  and  2  drachms. 
The  desired  coloration  is  effected  by  the  addition  of  bilberry 
or  elderberry  juice ;  otherwise  the  process  is  the  same  as  given 
for  Burgundy. 

Sherry  Wine. — Apple  juice,  50  quarts;  orange-flower  water, 
about  2  drachms ;  tartar  2  ozs.  and  4  drachms ;  rectified  alco- 
hol, 3  quarts;  crushed  raisins,  10  pounds;  acetic  ether,  1  oz. 
and  2  drachms.  The  process  is  the  same  as  for  Burgundy. 

Claret  Wine. — Apple  juice,  50  quarts ;  rectified  alcohol,  4 
quarts  ;  black  currant  juice,  2  quarts ;  tartar,  2  ounces  and  4 
drachms.  Color  with  bilberry  juice.  The  further  process  is 
the  same  as  for  Burgundy. 

Diseases  of  Cider. — Ciders  are  subject  to  diseases  which  may 
be  due  to  the  bad  quality  of  the  apples  used,  a  faulty  method 
of  manufacture,  or  bad  management  in  the  cellar. 

Badly  fermented  cider,  especially  such  as  has  merely  passed 
through  the  stage  of  tumultuous  fermentation,  or  has  been 
acidified  by  contact  with  the  air,  is  liable  to  produce  serious 
disorders.  The  first,  says  Dr.  E.  Decaisne,  being  heavy  and 
indigestible,  inflates  the  intestines  and  produces  diarrhoea  ;  the 
second,  though  of  a  sweet  taste  and  a  piquant  and  agreeable 
flavor,  does  not  quench  the  thirst,  but  excites  the  nervous 
system  and  produces  flatulency ;  the  third,  which  is  really 
spoiled  cider,  causes  inflammation  of  the  intestines  by  the 
large  amount  of  malic  and  acetic  acid  it  contains.  When  in 


MANUFACTURE    OF    CIDER.  413 

the  production  of  cider,  water  containing  organic  matter  has 
been  used,  putrid  fermentation  is  produced  in  the  mass,  the 
products  of  which  impart  some  very  deleterious  properties  to 
the  cider. 

Acidity  in  cider  may  be  due  either  to  an  excess  of  malic  acid 
or  of  acetic  acid. 

Some  ciders  contain  too  much  malic  acid  when  manufac- 
tured from  apples  not  sufficiently  ripe,  or  when,  in  mixing  the 
apples,  too  large  a  proportion  of  sour  apples  has  been  taken. 
In  both  these  cases  the  acidity  may  be  neutralized  by  adding 
to  the  apple-juice  3  ounces  and  8  drachms  of  potassium  tartrate 
per  22  gallons.  Sometimes  there  is  an  excess  of  acetic  acid, 
due  to  the  oxidation  of  the  alcohol  by  long  contact  with  the  air. 
This  defect  is  difficult  to  remedy.  It  might  have  been  pre- 
vented by  means  of  a  thin  coat  of  olive  oil,  as  previously  men- 
tioned, or  by  hermetically  closing  the  bungs.  The  acidity  will, 
however,  disappear  by  putting  in  the  bottles  a  pinch  of  bicar- 
bonate of  soda.  It  must,  however,  be  done  immediately  on 
detecting  the  defect. 

Viscosity  or  greasy  appearance  of  cider  is  recognized  by  the 
cider  becoming  stringy,  viscous  and  greasy,  and  is  due  to  too 
great  an  abundance  of  gummy  substances  in  the  fruit,  a  lack 
of  tannin,  and  finally  to  defective  fermentation.  In  order  to 
check  this  malady  from  its  first  appearance,  add  to  every  228 
quarts  of  the  cider  1  pint  of  alcohol  or  2  grammes  of  catechu 
dissolved  in  3  quarts  of  water.  Cider  may  be  prevented  from 
turning  viscous  by  the  addition  of  sugar  to  the  juice  when  it 
comes  from  the  press,  fermentation  being  thereby  promoted. 

The  cause  of  cider  turning  black  is  an  excess  of  oxide  of  iron, 
which,  on  coming  in  contact  with  air,  becomes  a  peroxide  and 
gives  the  beverage  a  brown  color.  The  oxide  of  iron  may 
have  been  introduced  into  the  cider  either  by  the  water  used 
in  making  it,  or  by  fruit  grown  on  ferruginous  soil.  By  mix- 
ing such  cider  with  12  drachms  of  powdered  oak  bark  per  22 
gallons,  a  quantity  of  tannin  is  introduced  which  combines 
with  the  iron  to  an  insoluble  product  that  settles  on  the  bot- 
tom of  the  barrel.  Tartaric  acid  may  also  be  used. 


414  MANUFACTURE    OF    VINEGAR. 

Turbidity  or  lack  of  clarification  of  cider  is  caused  by  too 
small  a  quantity  of  sugar  in  the  juice,  or  by  imperfect 
fermentation. 

In  rainy  seasons  the  apples  ripen  imperfectly  and  contain 
but  little  sugar.  Cider  prepared  from  such  fruit  generally  re- 
mains turbid.  During  seasons  in  which  abrupt  changes  of 
temperature  take  place,  and  also  when  cold  weather  sets  in 
very  early,  fermentation  does  not  progress  well,  and  clarifica- 
tion is  imperfect.  When  the  cider  remains  turbid  after  the 
first  racking  off,  add  a  solution  of  2  Ibs.  of  sugar  in  1  gallon 
of  water  to  every  132  gallons  of  the  liquid.  This  sugar  be- 
comes converted  into  alcohol  and  renders  the  cider  limpid. 
The  use  of  lead  salt,  formerly  much  in  vogue  in  Normandy, 
is  very  dangerous.  Persons  drinking  cider  thus  treated  fre- 
quently feel  sharp  pains  in  the  abdominal  region,  which  pre- 
sent all  the  symptoms  of  lead  colic  and  may  even  prove  fatal. 

An  admixture  of  lead  salt  is  readily  recognized.  Add  to 
the  suspected  cider  solution  of  potassium  iodide  ;  if  lead  salt 
be  present,  a  yellow  precipitate  of  iodide  of  lead  will  be 
formed. 

Adulteration  of  Cider. — According  to  most  of  the  authorities 
on  food,  cider  is  but  little  subject  to  adulteration.  Even  Has- 
sall,  who  generally  enumerates  under  each  article  of  food  a 
list  of  every  conceivable  adulteration  that  has  ever  been  found 
or  supposed  to  have  been  used  in  such  food,  only  speaks  of 
the  addition  of  water,  of  burnt  sugar  as  a  coloring  matter,  and 
of  the  use  of  antacids  for  the  correction  of  the  acidity  of  spoiled 
cider.  On  the  other  hand,  in  France  where,  as  previously 
mentioned,  the  consumption  of  cider  is  quite  large,  its  adulter- 
ation is  by  no  means  uncommon.  The  following  is  considered 
in  the  Paris  Municipal  Laboratory  as  a  minimum  for  the  com- 
position of  pure  cider : 

Alcohol,  per  cent,  by  volume 3.00 

Extracts,  in  grammes  per  liter 18  00 

Ash   .  1.7 


MANUFACTURE    OF    CIDER.  415 

This  is  for  a  completely  fermented  cider.  In  sweet  ciders 
the  content  of  sugar  should  exceed  the  limit  sufficiently  to 
make  up  for  the  deficiency  of  alcohol,  to  which  it  should  be 
calculated. 

In  the  samples  of  American  ciders  investigated  by  the 
United  States  Agricultural  Department  (see  pp.  393-4),  it  was 
fully  expected  to  find  a  number  preserved  with  antiseptics. 
This  supposition  failed  to  be  confirmed,  however,  for  no  sali- 
cylic acid  was  found,  and  in  but  one  case  was  any  test  ob- 
tained for  sulphites.  None  of  the  samples  fell  below  the 
standard  proposed  by  the  French  chemists,  given  above,  and 
no  metallic  or  other  adulteration  was  discovered. 

There  was,  however,  a  single  exception,  No.  4927  in  the 
table  of  analyses,  p.  394,  which  was  an  embodiment  in  itself 
of  nearly  all  the  adulterations  which  have  been  enumerated 
as  possible  in  cider.  It  was  handsomely  put  up  in  neatly- 
capped  bottles,  and  was  of  a  clear,  bright  color.  Its  tremendous 
"  head  "  of  gas  when  uncorked  gave  rise  at  once  to  the  sus- 
picion that  it  had  received  some  addition  to  produce  an 
artificial  pressure  of  gas.  The  low  content  of  free  acid, 
together  with  the  large  amount  of  ash  and  a  variable  content 
of  carbonic  acid  in  different  bottles,  established  the  fact  that 
bicarbonate  of  soda  had  been  added,  probably  a  varying 
quantity  to  each  bottle,  while  the  dose  of  sulphites  added  was 
so  large  that  a  bottle  stood  open  in  the  laboratory  all  through 
the  summer  without  souring. 

Manufacture  of  brandy  from  cider. — Brandy  is  a  mixture  of 
water  and  alcohol  produced  by  the  distillation  of  a  fermented 
liquor.  It  owes  its  aroma  to  the  essential  oil  peculiar  to  the 
substance  subjected  to  distillation. 

In  Normandy  the  heavy  ciders  only  are  distilled,  i.  e.,  those 
containing  the  most  alcohol. 

In  years  when  there  is  an  abundant  crop  of  apples,  it  will 
generally  be  found  of  advantage  to  distil  the  cider  made  from 
fallen  fruit  and  also  from  early  apples.  The  cider  yielded  by 
them  does  not  keep  well,  and  brings  a  very  low  price,  espe- 
cially when  there  is  a  large  product  from  late  apples. 


416  MANUFACTURE    OF    VINEGAR. 

Sour  ciders  should  not  be  distilled,  they  being  better  utilized 
for  the  manufacture  of  vinegar.  Spoiled  cider,  as  a  rule, 
makes  bad  brandy. 

Different  qualities  of  cider  should  be  distilled  separately. 
A  skilled  distiller  can  classify  them  by  the  taste,  and  separates 
them  in  order  to  obtain  brandy  of  first  and  second  qualities. 

The  cider  is  distilled  when  it  is  completely  fermented,  i.  e., 
when  the  largest  possible  quantity  of  sugar  has  been  converted 
into  alcohol.  Cider  from  early  apples  generally  ferments 
faster  than  that  from  late  apples  and  can  be  distilled  towards 
the  end  of  December,  i.  e.,  from  six  weeks  to  two  months  after 
it  has  been  made.  Cider  made  from  late  apples,  during 
December  and  January,  is  ready  for  distillation  three  or  four 
months  later,  i.  e.,  in  March  or  April. 

Preparation  of  the  juice  for  distillation. — When  there  is  an 
abundant  crop  of  apples  and  barrels  are  scarce,  the  juice  as  it 
comes  from  the  press  is  brought  into  large  open  vats  in  which 
fermentation  progresses  rapidly,  but  in  this  case  some  beer 
yeast  previously  mixed  with  a  small  quantity  of  cider  is  added 
to  each  vat  and  the  temperature  must  be  maintained  between 
59°  and  68°  F.  Under  these  conditions  the  juice  ferments 
very  promptly  and  may  be  distilled  eight  or  ten  days  later. 

Sometimes  the  whole  of  the  pulpy  mass  obtained  by  grind- 
ing the  apples  is  submitted  to  distillation.  In  order  to  accel- 
erate fermentation  a  small  quantity  of  hot  water  containing 
some  sugar  in  solution  is  added  to  the  mass,  also  one  or  two 
thousandths  of  sulphuric  acid,  the  latter  regulating  the  progress 
of  fermentation. 

Fermentation  being  finished,  the  mass  is  subjected  to  distil- 
lation. In  order  to  prevent  this  mass  from  adhering  to  the 
still  and  scorching,  distillation  must  be  conducted  as  slowly 
as  possible  and  a  small  quantity  of  straw  placed  upon  the 
bottom  of  the  still,  or,  better,  a  piece  of  cloth  to  prevent  direct 
contact  of  the  mass  with  the  heating  surface. 

Plums,  damsons,  etc.,  are  also  subjected  to  distillation  and 
produce  good  brandy.  They  ferment  more  slowly  than  wild 


MANUFACTURE    OF    CIDER.  417 

cherries  which  produce  the  well-known  cherry-bounce.  Atten- 
tion may  here  be  called  to  the  distillation  of  wild  plums,  which 
should  be  gathered  in  the  fall  when  the  leaves  begin  to  drop. 
Some  connoisseurs  consider  brandy  made  from  plums  equal  to 
that  from  cherries.  On  a  farm,  no  fruit  containing  sugar  should 
go  to  waste,  as  it  can  be  converted  either  into  brandy  or  vinegar. 

Distillation. — For  distilling  cider  on  a  small  scale  no  ex- 
pensive apparatus  is  necessary,  an  ordinary  still  answering  all 
requirements.  Cider  is  distilled  like  wine.  The  still  is  filled 
about  {  full  and  after  placing  the  head  in  position  the  joints 
are  carefully  luted  by  pasting  strips  of  cloth  or  even  paper  over 
them.  The  tub  holding  the  worm  is  tilled  with  cold  water  and 
the  fire  started.  The  vapors  escaping  from  the  boiling  liquid 
condense  in  the  worm  and  run  into  the  receiver.  Heating 
should  be  done  slowly,  in  order  to  vaporize  as  little  water  as 
possible,  and  especially  to  avoid  sudden  ebullition,  as  the  boil- 
ing liquid,  getting  into  the  head,  would  pass  through  the  worm 
and  become  mixed  with  the  liquor  already  distilled.  In  such 
an  event  it  would  be  necessary  to  begin  distillation  anew.  The 
operation  is  continued  until  the  liquid  produced  contains 
hardly  any  alcohol,  which  can  be  ascertained  by  the  use  of  the 
alcoholometer  or  by  the  taste.  It  is  unnecessary  to  say  that 
care  must  be  had  to  constantly  renew  and  keep  cold  the  water 
in  the  tub  holding  the  worm. 

Distillation  being  finished,  the  boiler  is  emptied,  and  after 
thorough  cleansing  is  refilled  for  a  second  operation. 

The  liquid  produced  by  successive  distillations  is  mixed 
together  and  brought  into  the  still  a  second  time,  whereby  a 
liquor  richer  in  alcohol  and  of  a  better  taste  is  produced.  It 
would  be  desirable  if  this  second  distillation  or  rectification 
could  be  effected  by  means  of  steam.  This  would  prevent  the 
empyreumatic  taste  which  is  often  noticed  in  apple-brandy. 
The  first  arid  last  runs  of  the  still  being  of  inferior  quality  are 
collected  separately  and  poured  back  into  the  still  when  re- 
filling for  the  next  operation. 

Calculations  have  been  made  to  establish  by  means  of  figures 
27 


418  MANUFACTURE    OF    VINEGAR. 

the  immense  advantage  offered  in  a  financial  point  of  view  by 
the  distillation  of  cider.  These  theoretical  calculations,  how- 
ever, are  frequently  very  deceptive.  If,  on  the  one  hand,  the 
producer  knows  the  content  of  alcohol  of  his  cider  and,  on  the 
other,  the  market  value  of  the  alcohol  and  of  the  cider,  it  will 
be  easy  for  him  to  decide  which  product  will  pay  him  best. 

Pear-cider. — The  manufacture  of  pear-cider  is  very  limited, 
and  no  great  future  can  be  promised  for  it,  as  even  when  most 
carefully  prepared  it  is  far  inferior  to  apple-cider  and  other 
fruit-wines.  Its  preparation  is  best  understood  in  England, 
and  how  little  it  is  appreciated  there  is  shown  by  the  fact  that 
three-fourths  of  the  quantity  manufactured  is  consumed  by  the 
farm-laborers.  But  any  one  who  has  large  pear  crops  at  his 
disposal  and  washes  to  use  a  portion  of  them  for  the  manufac- 
ture of  a  beverage  should  add  to  the  pear-must  one-quarter  its 
quantity  of  must  of  bitter-sweet  apples  or  a  few  quarts  of  black 
currant  juice,  which  will  improve  the  taste  of  the  cider  and 
its  keeping  qualities.  The  mode  of  preparation  is  the  same 
as  for  apple-cider,  though  still  greater  care  must  be  exercised 
in  the  choice  of  the  raw  material.  The  pears  must  have  a 
sufficient  content  of  sugar,  as  otherwise  the  cider  would  not  be 
sufficiently  rich  in  alcohol  and  at  the  same  time  they  must 
contain  a  bitter  substance  to  prevent  the  cider  from  turning 
sour  as  soon  as  the  conversion  of  the  sugar  is  effected.  Hence 
the  use  of  fine  table  pears  for  the  preparation  of  cider  would 
be  simply  a  waste  of  material.  The  only  varieties  suitable 
for  the  purpose  are  those  which  when  eaten  from  the  tree  pro- 
duce a  long-continued  sharp  heat  in  the  throat  and  lie  half  a 
day  undigested  in  the  stomach,  which,  however,  become  sweet 
by  long  storing  and  lose  enough  of  their  acerbity  to  be  no 
longer  disagreeable  to  the  palate.  In  England,  the  wild  pear 
grown  in  hedges  is  generally  used  for  the  purpose.  They 
must  be  ripe,  but  not  soft  or  mellow. 

In  the  northern  part  of  France  pear-must  is  sometimes  used 
for  the  preparation  of  "  port  wine,"  the  taste  of  which  is  very 
much  praised.  The  process  consists  in  heating  50  Ibs.  of  must 


PREPARATION    OF    FRUIT    WINES.  419 

to  between  176°  and  185°  F.  and  adding  5  pounds  of  raisins. 
At  this  degree  of  heat  must  and  raisins  are  brought  into  a 
barrel  which  is  tightly  bunged  and  placed  in  a  cool  place. 
When  in  the  course  of  a  day  the  must  is  cooled  to  59°  or  68° 
F.,  the  raisins,  which  are  generally  put  in  a  bag,  are  taken 
from  the  barrel  and  after  bruising  returned  (but  not  inclosed 
in  the  bag)  to  the  must,  which  is  then  allowed  to  ferment  for 
14  days.  The  wine  is  then  drawn  off  into  stone  jugs  which 
are  well  corked  and  sealed. 

Quince  Wine. — A  very  spicy  wine  can  be  prepared  from 
quinces  in  the  following  simple  manner :  Place  the  quinces 
for  a  few  moments  in  hot  water  and  then  rub  them  with  a 
cloth  to  remove  the  down.  Next  remove  the  cores  by  means 
of  a  knife  or  in  any  suitable  manner.  Now  pour  hot  water 
over  the  quinces  thus  prepared  and  boil  them  slowly  over  a 
moderate  fire  until  soft.  Then  press  out  the  juice  and  add 
white  sugar  in  the  proportion  of  1J  Ibs.  to  every  20  Ibs.  of 
fruits.  Allow  the  whole  to  ferment  in  a  cool  room  and  from 
time  to  time  add  some  sugar-water  during  the  process.  Clari- 
fication and  racking  off  is  effected  in  the  same  manner  as  with 
cider. 


CHAPTER  XXX. 

PREPARATION  OF  FRUIT  WINES. 

THE  manner  of  obtaining  the  juice  and  appliances  for  that 
purpose  have  already  been  described  in  the  previous  chapter. 

a.  From  small  fruits. — One  of  the  principal  objections  to 
wines  from  small  fruits  is  that  they  easily  turn.  This  can, 
however,  be  overcome  by  adding,  after  fermentation  is  finished, 
5.64  drachms  of  salicylic  acid  to  every  100  quarts.  By  in- 
creasing the  dose  to  8.46  drachms  less  sugar  can  be  added  to 
the  must,  which,  of  course,  makes  the  beverage  poorer  in  alco- 
hol. A  saving  of  sugar  can  be  further  effected  without  injury 


420  MANUFACTURE    OF    VINEGAR. 

to  the  keeping  quality  of  the  wine  by  a  suitable  mixing  of 
juices.  By  working,  for  instance,  the  juices  of  currant,  or  of 
raspberries  by  themselves,  a  considerable  addition  of  sugar, 
about  1  pound  per  quart,  has  to  be  made,  which  can,  however, 
be  reduced  one-half  by  mixing  with  a  juice  containing  some 
bitter  principle,  and  later  on  treating  the  wine  with  salicylic 
acid.  Thus  a  large  field  for  experimenting  is  opened  to  all, 
and  only  a  few  hints  will  here  be  given.  Raspberry -juice 
should  be  mixed  with  one-quarter  its  volume  of  blackberry- 
juice  ;  and  in  the  preparation  of  currant-wine  it  is  especially 
recommended  to  use  four-fifths  of  red  to  one-fifth  of  black  cur- 
ants,  the  wine  obtained  being  far  more  spicy  and  possessing 
better  keeping  qualities.  Moreover,  black  currants  used 
within  limits  are  an  excellent  material  for  improving  the 
flavor  of  almost  all  fruit-wines.  The  flavor  and  keeping  qual- 
ities of  fruit-wine  are  also  improved  by  throwing  a  couple  of 
handfuls  of  crushed  hazel-nuts  or  walnuts  into  the  barrel,  and 
also  by  the  addition  of  2  ounces  and  8  drachms  of  bitter  al- 
monds, the  peels  of  10  lemons,  3  ounces  and  5  drachms  of 
cassia,  and  a  few  handfuls  of  bruised  wild  plums.  By  these 
means  wine  with  a  moderate  content  of  alcohol  acquires  a 
strong  taste,  while  its  keeping  quality  is  at  the  same  time  im- 
proved. The  latter  can  also  be  effected  by  bringing  2  ounces 
and  3  drachms  of  tartar  into  the  barrel  during  fermentation. 
A  few  other  mixtures  of  juices  may  be  mentioned.  Blackberry- 
juice  is  better  adapted  to  ferment  by  itself  than  any  other  juice 
from  small  fruits,  but  by  the  addition  of  J  to  J  its  weight  or 
its  volume  of  strawberry-juice  the  aroma  of  the  wine  is  greatly 
improved.  Strawberry -juice  is  least  suitable  for  fermentation 
by  itself,  and  should  be  mixed  with  must  containing  a  bitter 
principle.  The  addition  of  J  of  the  volume  of  the  juice  of  the 
Siberian  crab-apple  (Pyrus  baccata)  can  be  highly  recommen- 
ded for  the  purpose,  it  being  especially  suitable  for  improv- 
ing the  keeping  quality  of  fruit-wine.  The  juice  of  rhubarb 
•stems  may  be  added  to  that  of  elderberries,  while  the  juice  of 
gooseberries  is  suitable  for  mixing  with  that  of  mulberries. 


PREPARATION    OF    FRUIT    WINES.  421 

Moreover,  a  combination  of  several  juices  may  also  be  used;  an 
excellent  wine  being,  for  instance,  prepared  from  equal  parts  of 
blackberry,  raspberry,  currant,  and  strawberry -juice,  with  an 
addition  of  walnuts  as  given  above.  In  the  receipts  for  the 
different  varieties  given  below,  the  customary  addition  of  sugar 
for  unmixed  fermentation  and  the  omission  of  salicylic  acid  is 
retained,  but  it  may  be  repeated  that  with  the  assistance  of  these 
means  the  cost  may  be  reduced  one-half.  In  order  to  avoid 
repetition,  the  following  general  rules  are  here  given,  which 
hold  good  not  only  for  the  preparation  of  wine  from  small 
fruits,  but  also  from  stone-fruits. 

The  fruit  to  be  used  should  be  sound  and  ripe,  though  not 
over-ripe,  and  must  be  freed  from  adhering  dirt  by  washing  in 
warm  water.  Large  quantities  are  best  expressed  by  means  of 
a  press,  while  for  small  quantities  a  bag  of  coarse  linen  is  suffi- 
cient, which  is  kneaded  and  squeezed  until  no  more  juice  runs 
out.  Over  the  residue  pour  as  much  hot  water  as  juice  is  ob- 
tained, and  after  allowing  it  to  stand  for  two  hours  press  again 
and  mix  the  juice  obtained  with  the  first.  Now  add  sugar  in 
the  proportion  of  one  pound  to  a  quart  of  juice,  and  bring  the 
whole  into  a  thoroughly  cleansed  barrel  previously  rinsed  out 
with  salicylated  water.  Fermentation  should  take  place  in  a 
room  having  a  uniform  temperature  of  from  59°  to  64°  F. 
During  this  process  lay  a  piece  of  gauze  upon  the  open  bung- 
hole  and  secure  it  by  means  of  a  stone,  piece  of  iron,  etc.,  which 
prevents  the  access  of  foreign  substances  to  the  must.  Every 
other  day  the  barrel  is  filled  up  to  the  bung-hole  with  sugar- 
water  prepared  in  the  proportion  of  J  Ib.  of  sugar  to  1  quart 
of  water.  As  soon  as  the  "hissing"  in  the  barrel  ceases,  bung 
the  barrel  tightly  and  after  14  days  draw  off  the  contents  into 
another  barrel  placed  in  the  same  room.  After  6  months  the 
wine  can  be  drawn  off  into  bottles,  being,  however,  8  days  pre- 
viously clarified  with  the  whites  of  a  dozen  eggs  or  1  oz.  of 
isinglass  slowly  dissolved  over  a  moderate  fire  in  1  pint  of  wine. 
Whatever  fining  is  used,  add  it  to  the  wine  with  constant  stir- 
ring. If  salicylic  acid  is  to  be  used,  it  is  best  done  in  the  man- 


422  MANUFACTURE    OF    VINEGAR. 

ner  described  for  cider  when  the  wine  has  acquired  the  desired 
degree  of  ripeness.  The  bottles  should  be  rinsed  with  salicyl- 
ated  water  and  closed  with  corks  previously  soaked  for  a  few 
hours  in  hot  salicylated  water.  Sealing  the  bottles  is  not  nec- 
essary, but  in  order  to  be  sure  that  the  corks  fit  closely,  shake 
each  bottle,  with  the  neck  downwards,  with  the  right  hand 
holding  the  left  under  the  cork.  If  the  slightest  moisture  is 
observed,  the  bottles  must  be  recorked,  as  carelessness  in  this 
respect  may  cause  a  portion  of  the  supply  of  wine  to  spoil. 
The  corked  bottles  are  laid  in  the  cellar. 

This  general  method,  according  to  which  all  kinds  of  wine 
from  small  fruits  can  be  prepared,  may  be  supplemented  by 
the  following  receipts  : 

Currant  Wine. — Among  all  varieties  of  berries  the  currant 
contains  the  largest  quantity  of  free  acid,  about  2  per  cent., 
and  comparatively  little  sugar,  about  6  per  cent.  The  propor- 
tion between  these  two  principal  constituents  is  very  unfavor- 
able for  the  manufacture  of  wine.  The  currant  juice  fer- 
mented by  itself  would  yield  a  product  which  does  not  deserve 
that  name. 

Free  the  thoroughly  ripe  currants  from  the  stems  and  after 
crushing  press  out  the  juice.  To  the  residue  add  twice  or  three 
times  as  much  water  as  juice  obtained  and  after  again  pressing 
add  the  juice  obtained  to  the  first.  Now  examine  the  juice 
as  to  its  content  of  acid  and  if  necessary  dilute  further  with 
water.  Then  calculate  the  sugar  in  the  manner  previously 
given.  Sugar  and  acid  having  been  brought  to  the  right 
proportion,  the  juice  is  allowed  to  ferment. 

Currant  wine  is  frequently  prepared  as  a  sweet  liqueur-wine, 
the  following  directions  being  much  used  for  the  purpose  : 
Juice  100  parts,  water  200,  sugar  100.  According  to  an  an- 
alysis by  Fresenius,  the  wine  thus  prepared  showed  after  two 
years  the  following  composition : — 


PREPARATION    OF    FRUIT    WINES.  423 

Alcohol 10.01 

Free  acid •    .  0.79 

Sugar 11.94 

Water 77.26 

100.00 

According  to  another  receipt,  17  J  Ibs.  of  thoroughly  ripe 
currants  freed  from  the  stems  are  bruised  in  a  wooden  vessel 
with  the  addition  of  3J  quarts  of  water.  The  paste  thus  ob- 
tained is  gradually  brought  into  a  bag  of  coarse  linen,  which 
is  laid  upon  an  oblique  board,  and  pressed  out  by  means  of  a 
rolling-pin.  The  press-residues  are  returned  to  the  wooden 
vessel  and,  after  adding  7  quarts  of  water,  thoroughly  worked 
with  a  pestle,  and  then  again  pressed  in  the  above  manner. 
The  juice  thus  obtained  is  brought  into  a  barrel  having  a 
capacity  of  34f  quarts,  a  solution  of  12  Ibs.  of  sugar  in  14 
quarts  of  water  is  then  added,  and  finally  sufficient  water  to 
fill  up  the  barrel  to  within  3  inches  of  the  bung.  After  cover- 
ing the  bung-hole  with  a  piece  of  gauze,  the  whole  is  allowed 
to  ferment  in  a  room  having  a  temperature  of  from  59°  to 
64°  F.  When  the  principal  fermentation  is  over,  the  barrel 
is  entirely  filled  with  water  and  closed  with  a  cotton  bung. 
The  wine  is  then  allowed  to  further  ferment  for  six  months  in 
a  cellar  having  a  temperature  of  from  54°  to  59°  F.,  when  it 
is  drawn  off  into  another  barrel  or  into  bottles.  By  adding  to 
the  fermenting  juice  J  Ib.  of  comminuted  raisin  stems  a  pro- 
duct closely  resembling  Tokay-wine  is  obtained. 

A  very  strong  beverage  is  obtained  by  adding  to  the  expressed 
juice  of  currants  twice  the  quantity  of  water  and  stirring  in  2 
tablespoonfuls  of  yeast.  Allow  the  juice  to  ferment  for  2  days ; 
then  strain  it  through  a  hair-sieve  and  after  adding  1  Ib.  of 
sugar  for  every  quart,  allow  it  to  ferment.  When  fermenta- 
tion is  nearly  finished,  add  French  brandy  in  the  proportion 
of  1  quart  to  40  quarts  of  the  juice,  and  bung  up  the  barrel 
two  days  later.  The  wine  is  ripe  in  four  months. 

According  to  another  receipt  the  currants  separated  from 


424  MANUFACTURE    OF    VINEGAR. 

the  stems,  are  pressed  and  the  juice  mixed  with  an  equal  quan- 
tity of  water.  Then  add  to  each  gallon  of  liquid  2J  Ibs.  of 
sugar,  2  ozs.  of  cream  of  tartar,  and  1  oz.  of  pulverized  nutmegs, 
with  1  quart  of  alcohol.  Allow  the  whole  to  ferment,  then 
fine  with  isinglass,  draw  off  and  bottle. 

Another  method  is  to  express  all  the  juice  possible,  then  take 
an  equal  amount  of  boiling  water,  and  pour  it  on  the  expressed 
fruit.  Let  it  stand  for  2  hours,  squeeze  out  as  much  as  there 
is  of  juice  and  mix;  then  add  4  Ibs.  of  brown  sugar  to  each 
gallon  of  Ihe  mixture  ;  let  it  stand  for  3  or  4  weeks,  until  fairly 
worked,  with  the  bung  out,  and  when  it  is  done  working,  bung 
it  up,  then  place  it  in  a  cool  cellar. 

Strawberry-wine. — For  the  preparation  of  wine  very  fragrant 
strawberries  should  be  selected.  The  aroma  of  the  strawberry 
is  so  delicate  that  it  readily  undergoes  a  change  and  soon  dis- 
appears entirely.  Hence  to  secure  it  and  transfer  it  into  the 
juice  the  strawberry  requires  special  treatment,  whereby  neither 
the  content  of  acid  nor  that  of  sugar  is  taken  into  considera- 
tion. This  treatment  consists  in  mixing  the  sound,  ripe  berries, 
without  previous  crushing  or  bruising,  with  the  same  weight  of 
pulverized  sugar  and  allowing  the  mixture  to  stand  in  a  glass 
or  stoneware  vessel  in  a  cool  place  until  all  the  sugar  is  dis- 
solved to  a  clear  syrup  in  which  the  shrunk  and  tasteless 
berries  float.  To  separate  the  latter,  strain  the  juice  through 
a  woolen  cloth  previously  rinsed  with  some  lemon-juice  or 
tartaric  acid,  dilute  with  the  same  quantity  of  water,  bring 
the  acid  to  0.5  per  cent.,  and  subject  the  whole  to  fermenta- 
tion in  the  usual  manner  at  a  temperature  of  from  50°  to 
59°  F. 

Some  allow  the  berries  to  ferment  with  the  juice,  but  the 
wine  obtained  is  somewhat  harsh  and  not  as  delicate. 

By  finally  adding  to  the  finished  wine  from  4  to  5  per  cent, 
of  rock-candy,  a  liqueur-wine  is  obtained  which,  as  regards 
aroma,  cannot  be  surpassed,  and  is  especially  liked  by  ladies. 

Excellent  strawberry  wine  is  also  obtained  according  to  the 
following  directions  :  Press  out  10  Ibs.  of  different  varieties  of 


PREPARATION    OF    FRUIT    WINES.  425 

small  and  large  cultivated  strawberries,  which  give  about  2J 
quarts  of  juice.  Pour  water  over  the  residue  and  press  again, 
so  as  to  obtain  about  3  quarts  more  of  juice  or  a  total  of  5J 
quarts.  Next  dissolve  4  pounds  of  rock  candy  in  5  quarts  of 
cold  water,  bring  the  solution,  together  with  the  5J  quarts  of 
juice,  into  a  small  cask,  and  allow  the  whole  to  ferment  in  a 
cellar  having  a  temperature  of  61°  F.  In  four  weeks  the  wine 
is  ready  for  drawing  off  into  bottles.  It  is  of  a  beautiful  pale 
yellow  color  and  possesses  an  excellent  bouquet,  and  if  made 
sparkling  furnishes  an  excellent  beverage. 

According  to  a  receipt  in  the  "  Weinzeitung,"  40  quarts  of 
strawberries  and  41  quarts  of  water,  with  an  addition  of  12  Ibs. 
of  sugar,  3J  ozs.  of  tartar,  and  a  gallon  of  whiskey  free  from 
fusel  .oil  are  allowed  to  ferment  and  the  resulting  wine  i& 
treated  in  the  usual  manner. 

Another  method  is  to  pour  1  quart  of  hot  water  upon  1 
quart  of  crushed  strawberries  and  pressing  out  after  allowing 
the  mass  to  stand  for  2  days.  Then  add  to  every  quart  of 
juice  1  Ib.  of  sugar,  and  to  every  40  quarts  of  juice  the  grated 
peel  and  juice  of  2  lemons  and  2  oranges  and  4  quarts  of 
French  brandy.  Allow  the  whole  to  ferment,  and  treat  the 
resulting  wine  in  the  usual  manner. 

Gooseberry-wine. — The  proportion  between  sugar  and  acid 
is  somewhat  more  favorable  in  the  gooseberry  than  in  the- 
currant,  but  not  sufficiently  so  as  that  the  pure  juice  would 
yield  a  good  wine  by  fermentation.  Hence  the  juice  must  be 
converted  into  suitable  must,  as  regards  sugar  and  acid,  in 
accordance  with  the  rules  previously  given.  The  yellow  varie- 
ties are  preferable,  they  alone  having  a  distinctly  vinous  taste  ; 
the  wine  obtained  from  the  red  and  green  varieties  being 
somewhat  insipid.  The  juice  is  obtained  in  the  same  manner 
as  from  currants,  the  berries  being  bruised,  the  juice  allowed 
to  run  off  and  the  residue  washed  several  times  with  water,  so 
that  each  volume  of  juice  receives  an  addition  of  1  volume  of 
water,  though  as  the  mixed  juice  has  to  be  tested  as  to  its- 
content  of  acid,  the  direction  in  regard  to  the  addition  of 


426  MANUFACTURE    OF    VINEGAR. 

ivater  need  not  be  accurately  followed.  The  must  may  contain 
-as  much  as  30  per  cent.,  because  the  fermentation  of  goose- 
berry-must is  generally  carried  on  in  the  warmer  season  of 
the  year,  so  that  all  or  the  greater  portion  of  the  sugar  fer- 
ments and  the  wine,  on  account  of  the  quantity  of  alcohol 
formed,  will  keep  for  an  almost  indefinite  time.  Gooseberry- 
wine  made  from  must  rich  in  sugar  generall}7  acquires  by  age 
an  odor  of  Madeira-wine,  which  frequently  deceives  even  con- 
noisseurs. 

Gooseberry-wine,  like  currant-wine  being  liked  sweet,  a 
larger  quantity  of  sugar  may  be  added  to  the  must  from  the 
^tart,  though  for  a  quicker  process  of  fermentation  it  is  better 
io  add  the  desired  quantity  of  sugar  to  the  fermented  wine. 
If  the  must  has  been  made  quite  sweet,  so  that  a  wine  rich  in 
alcohol  is  formed,  no  fear  need  be  had  of  the  wine  fermenting 
anew  on  account  of  the  addition  of  sugar. 

There  are  a  number  of  receipts  for  the  preparation  of  goose- 
berry-wine, but  when  more  closely  examined  the  products  pre- 
pared according  to  them  will  be  found  either  more  or  less  rich 
in  alcohol,  or  to  contain  more  or  less  free  acid,  and  to  be  either 
sweet  or  not  sweet,  so  that-  the  proportion  can  evidently  be 
-changed  in  any  manner  desired.  It  is  further  evident  that 
nothing  is  gained  thereby  as  regards  quality,  because  the  type 
for  all  artificial  wines  is  grape  wine  obtained  in  a  good  season. 
In  such  wines  the  proportions  between  alcohol  and  free  acid 
are  well  known  and  within  such  narrow  limits  that  they  cannot 
be  essentially  exceeded  on  either  side,  and  they  alone  can  serve 
as  a  basis  for  the  rational  preparation  of  gooseberry  wine  as 
well  as  of  all  artificial  wines.  With  the  aroma  or  bouquet  which 
is  to  be  imparted  to  such  wine  it  is,  of  course,  different ;  but  no 
special  directions  are  required,  as  every  one  manages  it  accord- 
ing to  his  own  taste  or  according  to  that  of  those  who  buy  and 
drink  the  wine.  Thus  it  is  also  with  the  addition  of  sugar ;  one 
likes  a  sweet  wine,  the  other  one  less  sweet,  and  the  third  one 
without  any  sugar.  The  principal  aim  is  to  prepare  a  wine 
which  contains  the  necessary  quantity  of  alcohol  to  insure  its 


PREPARATION    OF    FRUIT    WINES.  427 

keeping  properly,  and  the  power  of  resistance  against  decom- 
posing influences,  and  from  which  the  greater  portion  of  the 
fermentable  substances  is  removed  by  fermentation.  In  most 
oases  the  natural  conditions  are  of  great  use  in  this  respect, 
for  in  order  to  decrease  the  content  of  free  acid  it  becomes 
necessary  to  dilute  the  fruit  juices,  whereby  the  quantity  of  fer- 
mentable substances  is  also  relatively  decreased,  and  sometimes 
even  to  such  an  extent  that  they  do  not  suffice  for  the  complete 
fermentation  of  the  sugar.  Such  wine,  if  not  wanting  in  alco- 
hol, will  keep  for  an  almost  indefinite  time  and  may  be  ex- 
posed to  the  access  of  air  and  a  high  temperature  without  the 
appearance  of  the  formation  of  acetic  acid. 

Gooseberry  Champagne. — The  taste  of  this  beverage  closely  re- 
sembles that  of  genuine  champagne.  There  are  several  modes 
of  its  production.  In  France  a  light  wine  which  does  not  con- 
tain too  many  fermentable  substances  is  used.  Somewhat  less 
than  2  per  cent,  of  sugar,  or  about  15  grammes  to  a  bottle  of 
800  cubic  centimeters'  capacity,  is  dissolved  in  the  wine  and  the 
latter  drawn  off  into  strong  champagne  bottles,  which  are  then 
hermetically  corked  and  tied  with  twine.  The  wine  is  then 
allowed  to  ferment  in  a  room  having  a  temperature  of  from 
77°  to  99°  F.  When  fermentation  is  finished,  the  bottles  are 
brought  into  a  cool  cellar  and  placed  first  horizontally  and 
then  gradually  bottom  uppermost  so  that  the  yeast  may  collect 
on  the  cork  and  the  wine  become  clear.  When  all  the  yeast 
is  precipitated  to  the  neck  of  the  bottle,  the  sediment  is  care- 
fully removed — degorgie  as  it  is  termed — by  first  raising  the 
string  securing  the  cork  and  then  the  latter,  the  bottle  being 
held  in  a  horizontal  position.  The  cork  being  no  longer  held 
by  the  string  is  forced  out  together  with  the  deposit  of  yeast, 
while  the  clear  wine  impregnated  with  carbonic  acid  remains 
behind.  To  prevent  the  unavoidable  loss  of  wine,  the  cork, 
together  with  the  yeast  and  wine  forced  out,  is  collected  in  an 
upright  barrel  with  a  large  aperture,  towards  which  the  mouth 
of  the  bottle  is  held  during  the  operation. 

The  wine  thus  impregnated  with  carbonic  acid,  however,  is 


428  MANUFACTURE    OF    VINEGAR. 

not  yet  champagne  ;  it  only  becoming  so  after  the  addition  of 
a  solution  of  fine  rock-candy  in  brandy  with  which  the  bottle 
is  filled  up.  Each  bottle  after  receiving  the  necessary  quantity 
of  the  solution,  or  liqueur  as  it  is  termed,  is  at  once  closed  with 
a  cork  which  is  secured  with  twine  or  wire.  Removing  the 
deposit  of  yeast  is  the  most  difficult  portion  of  this  operation, 
long  experience  being  required  before  the  workman  possesses 
the  necessary  skill. 

According  to  another  method,  which  is  also  called  the  im- 
pregnating method,  the  sugar  required  for  sweetening  is  dis- 
solved in  the  wine,  and  after  clarifying  the  solution  by  filtering 
through  paper  pulp  in  a  bag,  or,  if  necessary,  with  some  isin- 
glass, it  is  taken  to  the  impregnating  apparatus,  one  similar  to 
that  used  for  mineral  water  answering  the  purpose.  The  wine 
is  then  saturated  under  a  pressure  of  4J  to  5  atmospheres  with 
the  desired  quantity  of  carbonic  acid  and  at  once  drawn  off 
into  bottles,  which  are  corked  and  wired  as  above. 

The  advantage  of  this  last  named  method  consists  in  the 
rapidity  with  which  champagne  can  be  made,  30  to  36  months 
being  required  for  the  first  method  before  the  champagne  is 
ready  for  transportation. 

The  following  method  is  the  most  simple  of  all,  but  does 
not  yield  as  fine  a  product.  Each  bottle  is  finished  by  itself 
and  no  special  apparatus  is  required.  The  wine  is  sweetened 
and  clarified  in  the  same  manner  as  in  the  impregnating 
method  and  then  drawn  off  into  bottles.  In  case  the  wine  is 
not  rich  enough  in  alcohol,  the  content  of  the  latter  may  be 
increased  by  10  per  cent. 

After  having  filled  the  bottles  about  1.52  cubic  inches  less 
than  generally,  add  first  to  each  bottle  11  drachms  of  pure 
crystallized  bicarbonate  of  potash  and  immediately  afterwards 
1  oz.  of  pure  crystallized  tartaric  acid  in  pieces.  Then  close 
the  bottle  with  the  cork  and  secure  the  latter  by  tying  or  wir- 
ing it  crosswise.  The  potash  and  acid  are  now  brought  to 
solution  by  gently  swinging  the  bottle  to  and  fro,  the  contents 
becoming  at  the  same  time  turbid  by  the  separation  of  bitar- 


PREPARATION    OF    FRUIT    WINES.  429 

trate  of  potash.  By  placing  the  bottle  bottom  upwards,  the 
separated  tartar  is  collected  as  much  as  possible  upon  the 
lower  surface  of  the  cork,  and  after  the  wine  is  clear,  removed 
in  the  same  manner  as  described  in  the  first  method.  It  is 
not  absolutely  necessary  to  remove  all  the  tartar,  as  it  settles 
on  the  bottom  and  the  champagne  will  pour  out  clear. 

According  to  any  of  these  methods  all  fruit  wines  can  be 
converted  into  champagne  or  sparkling  wines. 

Semler  gives  the  following  directions  for  the  preparation  of 
gooseberry  champagne.  Pour  20  quarts  of  warm  water  over 
20  quarts  of  crushed  gooseberries  and  add  6  Ibs.  of  sugar,  4| 
Ibs.  of  honey,  1  oz.  of  pulverized  tartar,  J  oz.  of  dried  lemon 
peel,  and  f  oz.  of  dried  orange  peel.  After  standing  for  two 
days  strain  the  mixture  through  a  hair-sieve  into  a  barrel  and 
add  2  quarts  of  French  brandy.  When  the  "  hissing  "  in  the 
barrel  ceases,  clarify  the  wine  and  after  a  few  days  draw  it  off 
into  bottles,  securing  the  corks  with  wire.  Before  filling  the 
bottles  throw  a  piece  of  sugar  and  J  drachm  of  bicarbonate  of 
soda  into  each. 

Raspberry  Wine. — Raspberries  have  such  an  agreeable  and 
refreshing  taste  and  odor  that,  while  they  are  not  very  sweet 
and  the  proportion  of  acid  to  sugar  is  not  very  favorable,  they 
are  great  favorites.  Their  aroma  passes  into  the  wine  and 
would  be  even  too  predominant  if  for  the  preparation  of  wine 
the  juice  had  not  to  be  strongly  diluted  with  water  in  order  to 
decrease  the  acid. 

As  in  all  other  fruit,  the  quality  of  the  raspberry  depends  on 
the  weather,  and  when  this  is  favorable  during  the  time  of  the 
development  and  maturing  of  the  fruit,  the  latter  is  sweet  and 
palatable,  but  in  cold  and  wet  seasons,  sour  and  harsh.  No 
other  fruit  suffers  as  much  from  such  conditions  as  the  rasp- 
berry. 

We  have  the  wild  and  -cultivated  raspberry.  The  wild  rasp- 
berry is  smaller  than  the  cultivated  but  possesses  a  stronger 
aroma,  but  unfortunately  is  too  frequently  infested  with  the 
larva  of  many  insects  to  render  it  always  palatable.  The  cul- 


430  MANUFACTURE    OF    VINEGAR. 

tivated  raspberry  is  considerably  larger,  and  is  less  attacked 
by  worms,  but  possesses  less  aroma  and  is  frequently  even 
watery. 

To  obtain  the  juice  for  the  preparation  of  wine  the  thoroughly 
ripe  raspberries  are  crushed  to  a  paste  in  a  wooden  tub  by 
means  of  a  wooden  pestle.  To  separate  the  grains,  the  paste  is 
forced  through  a  fine  wire  sieve,  which,  in  order  to  protect  it 
from  the  acid  is  best  provided  with  a  coat  of  asphalt  or  shellac 
varnish.  It  is,  however,  no  disadvantage  to  allow  the  grains 
to  ferment  with  the  pulp,  some  tannin  being  thereby  intro- 
duced into  the  wine,  which  under  certain  circumstances  may 
be  even  desirable. 

The  content  of  acid  in  the  raspberry  varying  considerably  in 
different  years,  a  test  of  the  juice  in  this  respect  becomes  abso- 
lutely necessary  in  order  to  enable  one  to  dilute  it  in.  the  cor- 
rect proportion  with  water.  For  this  purpose  press  out  a  small 
quantity  of  the  crushed  raspberries  and  determine  the  acid  in 
the  manner  previously  given.  The  sugar  contained  in  the  rasp- 
berry need  not  be  taken  into  consideration,  since  by  dilution  it 
is  reduced  to  1  per  cent,  and  still  less.  The  must  is  simply 
brought  up  to  25  per  cent,  of  fruit-sugar  and  allowed  to  fer- 
ment in  the  usual  manner.  The  treatment  of  the  wine  after 
fermentation  is  the  same  as  for  other  fruit  wanes. 

Blackberry  wine  is  prepared  in  the  same  manner  as  raspberry 
wine.  Of  the  numerous  directions  for  its  preparation  we  give 
the  following :  Gather  the  berries  on  a  dry  day,  crush  them 
with  the  hand  into  a  kettle,  and  add  just  enough  hot  water  to 
cover  the  mass.  Then  add  a  handful  of  bruised  raisins  and  a 
handful  of  strawberry  leaves,  from  the  heart  of  the  mother 
plant,  or,  still  better,  from  the  suckers,  and  allow  the  mass  to 
stand  for  four  days,  when  a  crust  of  yeast  will  have  formed  on 
the  surface.  The  mass  is  now  pressed  out  and  sugar  in  the 
proportion  of  1  pound  to  every  4  quarts  added.  Fermentation 
is  allowed  to  go  on  for  two  weeks,  when  the  barrel  is  bunged 
up  and*  the  wine  drawn  off  after  six  months.  During  fermen- 
tation, and  especially  in  the  beginning  of  it,  care  must  be  had 
to  fill  up  the  barrel. 


PREPARATION  OF  FRUIT  WINES.  431 

To  make  from  blackberries  a  beverage  resembling  port-wine 
the  following  method  is  recommended  :  Press  out  the  juice  and 
allow  it  to  stand  for  36  hours.  While  fermenting  during  this 
time  remove  all  scum  from  the  surface.  Now  add  of  water, 
one-fourth  the  quantity  of  juice,  and  3  pounds  of  brown  sugar 
to  every  4  quarts  of  fluid  and  filter  after  32  hours.  Fermen- 
tation, which  requires  but  a  few  days,  being  finished,  bung  up 
the  barrel  tightly  and  after  six  months  draw  off  the  wine. 
The  latter  improves  by  age. 

Mulberry  Wine. — Press  the  juice  from  the  fruit,  dilute  with 
the  same  quantity  of  water,  add  1  pound  of  sugar  for  every 
quart  of  liquid,  and  boil  the  whole  j-  hour.  Then  add  for 
every  100  quarts,  3  quarts  of  alcohol,  6J  ounces  of  tartar,  1 
ounce  of  cassia,  and  J  ounce  of  bruised  bitter  almonds,  and 
allow  the  whole  to  ferment.  The  further  treatment  of  the 
wine  is  the  same  as  for  other  fruit-wines. 

Elderberry  Wine. — Boil  equal  quantities  of  berries  and  water 
one-half  hour,  pour  the  whole  into  a  hair-sieve,  press  the  pulpy 
portion  of  the  berries  gently  through  with  the  hand  and  re- 
move the  residue.  Compound  the  strained  juice  with  sugar 
in  the  proportion  of  {  pound  to  1  quart,  and  boil  20  minutes. 
As  soon  as  cool  bring  it  into  a  barrel  to  ferment.  Fermenta- 
tion being  finished,  paste  stiff  brown  paper  over  the  bung- 
hole,  and  after  eight  weeks  draw  off  the  wine  in  bottles. 

Another  method  is  to  boil  50  quarts  of  water,  10  quarts  of 
elderberries,  40  pounds  of  sugar,  5  ounces  of  pulverized  ginger^ 
and  2J  ounces  of  cloves  for  1  hour,  with  constant  skimming. 
Then  bring  the  liquid  together  with  4  pounds  of  crushed  rai- 
sins into  a  barrel  and  allow  it  to  ferment.  At  the  termination 
of  the  fermentation  it  will  yield  a  wine  similar  to  the  Cyprus^ 
or  Greek-wine. 

Juniperberry  Wine. — 70  quarts  of  water,  35  pounds  of  crushed 
raisins,  10  quarts  of  juniperberries,  4  ounces  of  tartar,  1  quart 
of  French  brandy,  and  a  handful  of  fresh  marjoram  leaves 
are  brought  into  a  barrel  and  the  mixture  is  allowed  to  fer- 
ment for  12  hours. 


432  MANUFACTURE    OF    VINEGAR. 

Rhubarb  Wine. — Add  to  every  5  pounds  of  the  thinly-sliced 
stalks  2 \  quarts  of  soft  water  and  bring  the  whole  into  a  clean 
wooden  vessel.  Cover  the  latter  and  stir  the  contents  with  a 
wooden  stick  three  times  daily  for  one  week.  Then  pass  the 
fluid  through  a  wide-meshed  sieve  and  add  to  every  3  quarts, 
4  pounds  of  white  sugar,  the  juice  of  2  lemons,  and  the  peel 
of  1  lemon  rubbed  upon  sugar.  Allow  the  mixture  to  ferment 
in  a  barrel,  and  after  clarifying,  draw  the  wine  off  into  bottles 
in  March. 

The  variety  of  rhubarb  known  as  Victoria  is  best  adapted 
for  the  preparation  of  wine,  which  can  also  be  effected  accor- 
ding to  the  following  directions  :  Cut  up  the  stalks  and  express 
the  juice.  To  every  gallon  of  juice  add  1  gallon  of  soft  water 
and  7  pounds  of  brown  sugar.  Bring  the  mixture  into  a  bar- 
rel and  allow  it  to  ferment  until  clear,  with  the  bung  out,  keep- 
ing the  barrel  filled  with  sweetened  water  as  it  works  over  ; 
then  bung  the  barrel  tightly  or  draw  the  wine  off  into  bottles. 
It  makes  an  agreeable  and  healthful  wine  affording  a  good 
profit,  as  nearly  1800  gallons  of  wine  may  be  obtained  from 
each  acre  of  well-cultivated  plants.  The  stalks  will  furnish 
about  three-fourths  their  weight  in  juice. 

Tomato  Wine. — Press  out  the  juice  from  ripe  tomatoes,  add 
to  each  quart  of  it  1  pound  of  brown  sugar,  and  allow  the 
whole  to  ferment.  After  three  months  the  wine  can  be  drawn 
off  into  bottles. 

Parsnip  Wine. — Cut  12  pounds  of  parsnips  into  thin  pieces, 
add  15  quarts  of  water  and  boil  until  soft.  Then  press  out 
the  juice  and  after  straining  through  a  hair-sieve  sweeten  with 
j  pound  of  sugar  per  quart.  After  again  boiling  for  j  hour  it 
is  brought,  when  cold,  into  a  barrel  and  a  tablespoonful  of 
yeast  is  added.  Stir  the  juice  daily  for  10  days,  then  bung  up 
the  barrel  tightly  and  after  six  months  draw  off  the  wine  into 
bottles. 

In  the  same  manner  wine  may  be  prepared  from  carrots, 
clover  heads,  corn  stalks,  etc.  It  is,  however,  recommended 
to  add  to  the  juice  some  aromatic  substance  such  as  a  handful 


PREPARATION    OF    FRUIT    WINES.  433 

of  marjoram,  almonds,  plum  kernels,  currants,  walnuts,  ginger, 
or  still  better  a  few  quarts  of  black  currant  juice. 

b.  From  Stone  Fruits.  Cherry  Wine. — Stone  sweet  cherries 
and  after  crushing  the  pulp  to  a  paste  allow  it  to  ferment  in 
stoneware  pots  for  12  hours.  Then  press  out  the  juice,  which 
is  returned  to  the  pots  and  allowed  to  stand  until  yeast  fungi 
rise  to  the  surface.  Now  add  1  pound  of  sugar  to  every  3 
quarts  of  must,  bring  the  latter  into  a  barrel  and  allow  it  to 
ferment  8  days.  Then  rack  the  wine  into  bottles  and  keep  in 
a  cool  place.  The  preceding  is  the  method  followed  in  Eng- 
land where  pure  cherry  wine  is  made.  It  may,  however,  be 
remarked  that  it  is  somewhat  insipid.  A  mixture  of  the  juice 
of  cherries  with  that  of  the  raspberry  or  currant  can,  however, 
be  highly  recommended,  it  yielding  a  beverage  similar  to  port 
wine.  It  is  an  American  receipt  and  much  preferable  to  the 
English.  Press  the  freshly  gathered  cherries,  black  or  red, 
but  selecting  those  with  the  softest  pulp,  without  crushing  the 
stones.  To  the  juice  obtained  add  one-eighth  of  its  quantity 
each  of  raspberry  and  black  currant  juice,  and  sweeten  with 
lump  sugar  in  the  proportion  of  1  pound  to  2J  quarts  of  juice. 
The  whole  is  then  brought  into  a  barrel  to  ferment.  When 
fermentation  is  finished  close  the  barrel  tight  and  allow  it  to 
rest  for  three  months.  Then  clarify  the  wine  and  draw  it  off 
into  bottles.  It  is  fit  to  drink  in  six  weeks. 

Morello  Wine. — Press  60  pounds  of  morellos  so  as  to  crush 
the  stones,  mix  the  juice  obtained  with  20  quarts  of  sherry 
wine  and  the  same  quantity  of  warm  water,  and  bring  the 
whole  into  a  barrel  to  ferment.  Suspend  in  the  barrel  a  bag 
containing  1J  ounces  each  of  cinnamon,  powdered  nutmeg 
and  mace,  allowing  it  to  remain  until  drawing  off  the  wine. 
The  latter  is  very  palatable  in  two  months  after  fermentation 
is  finished. 

Plum  Wine. — Not  all  varieties  of  plums  are  suitable  for  the 

preparation  of  wine,  but  the  Heine  Claude  and  Mirabelle  can 

be  highly  recommended,  the  latter  especially  making  as  spicy 

and  agreeable  wine  as  any  variety  of  fruit.     With  the  almost 

28 


434  MANUFACTURE    OF    VINEGAR. 

innumerable  varieties  of  plums  it  is  not  possible  to  say  which 
are  suitable  for  the  preparation  of  wine  and  which  are  not.  It 
can  only  be  determined  by  experiment,  though  right  sweet 
varieties  only  should  be  chosen.  In  this  country  the  small 
sweet  variety  known  as  the  wheat  plum,  etc.,  is  frequently 
used  for  the  purpose.  The  process  is  as  follows :  Stone  the 
plums,  then  bruise  the  pulp,  and  add  to  every  8  pounds  of  the 
latter  3  quarts  of  hot  water.  After  2  days  press  out  the  juice 
and  add  to  every  two  quarts  of  it  one  pound  of  sugar.  Now 
bring  the  juice  into  a  barrel  in  a  cool  room  and  add  the 
crushed  kernels  of  -f-  of  the  stones.  Allow  the  whole  to  fer- 
ment completely.  After  12  months  the  wine  is  clarified  and 
drawn  off  into  bottles,  each  of  which  receives  a  small  piece  of 
sugar,  which  improves  the  keeping  qualities  of  .the  wine. 

Apricot  and  Peach  Wines. — Both  these  varieties  of  fruit  are 
used  when  nearly  ripe.  Remove  the  stones  and  crush  the  pulp 
to  a  paste.  For  every  8  pounds  of  the  latter  add  1  quart  of 
fresh  soft  water,  and  let  the  mass  stand  24  hours.  Then 
press  out  the  juice,  add  for  every  2  quarts  of  it  1  pound  of 
sugar,  and  allow  it  to  ferment.  During  fermentation  it  is  rec- 
ommended to  throw  a  handful  of  the  crushed  stones  into  the 
barrel,  which  gives  to  the  product  a  more  spicy  flavor. 

Sloe  or  Wild  Plum  Wine. — This  beverage  is  not  to  be  de- 
spised if  prepared  in  the  manner  given  for  plum  wine.  The 
sloes  must,  however,  remain  on  the  bushes  until  after  the  first 
frost,  which  sweetens  them. 


PART  III. 

CANNING  AND  EVAPORATING  OF  FRUIT. 
MANUFACTURE  OF  CATSUPS,  FRUIT- 
BUTTERS,  MARMALADES,  JELLIES, 
PICKLES,  AND  MUSTARD.     PRES- 
ERVATION OF  MEAT,  FISH, 
AND  EGGS. 


CHAPTER  XXXI. 

PRESERVATION  OF  FRUIT. 

THE  use  of  hermetically  closed  tin  cans  for  preserving  fruit 
has  become  of  great  commercial  importance.  Before  discuss- 
ing it,  the  various  ways  which  have  proved  more  or  less  satis- 
factory for  household  purposes  will  be  briefly  mentioned. 
The  following  rules  apply,  however,  to  all  methods : — 

1.  The  fruit  must  be  gathered  in  dry  weather  and  when  free 
from  dew.     It  is  to  be  kept  as  free  from  dust  as  possible. 

2.  Absolutely  sound  fruit,  not  over-ripe,  should  only  be  se- 
lected. 

3.  The  fruit  should  be  preserved  immediately  after  gather- 
ing. 

4.  The  utensils  used  must  be  kept  scrupulously  clean. 

5.  The   preserving  vessels  should    not   be  placed  directly 
upon  the  fire. 

6.  A  good  quality   of  white  sugar  only  should    be   used  ; 
brown  sugar  injuring  the  taste  and  color  of  the  fruit. 

7.  Copper  or  enameled  pans  alone  should  be  used  for  boil- 

"(435) 


436  MANUFACTURE    OF    VINEGAR. 

ing,  if  the  latter  is  not  effected   in  glass.     The  spoons  should 
be  of  wood  or  of  bone. 

8.  The  jars  or  cans  should  be  thoroughly  rinsed,  best  with 
salicylated  water,  and  if  corks  are  to  be  used  they  should  be 
perfectly  sound  and  scalded  in  hot  water  to  which  some  sali- 
cylic acid  has  been  added. 

9.  Small  jars  or  cans  are  preferable  to  large  ones,  and  they 
should  be  kept  in  a  dark,  cool,  dry  place. 

Bottled  fruits  should  always  be  sterilized  for  10  minutes, 
from  the  time  the  boiling-point  is  reached,  in  the  case  of 
J-bottles,  12  minutes  for  J-bottles,  and  15  minutes  for  full- 
sized  bottles.  Only  in  the  case  of  halved  apricots  and  peaches 
and  similar  fruits  that  lie  closely  together,  should  a  few 
minutes  extra  be  allowed.  Fruits  that  change  color  when 
heated,  for  instance,  white  .pears,  peaches  and  gooseberries 
should  be  separated  after  sterilizing  in  order  to  accelerate 
cooling. 

First  may  be  mentioned  the  old  French  method,  known  as 
au  Baine-Marie,  which  on  account  of  its  simplicity,  is  still 
much  used.  Berries  require  no  preparation,  but  peaches, 
apricots  and  plums  must  be  stoned  and  halved,  and  cherries 
and  small  plums  stoned.  Apples  arid  pears  are  peeled  and 
quartered  and  immediately  thrown  into  boiling  water  for  4 
minutes  to  bleach,  They  are  then  laid  a  few  minutes  upon  a 
sieve  to  dry,  and  brought,  like  other  fruit,  by  means  of  a  spoon 
into  wide-necked  glass  jars  which  are  rilled  to  within  2  inches 
of  the  edge.  In  placing  the  fruit  in  the  jar  press  it  well  to- 
gether. The  empty  space  is  then  filled  up  with  hot  syrup 
composed  of  2  parts  of  sugar  and  1  part  of  water,  and  the  jars, 
after  heating  them  somewhat  upon  a  stove,  are  placed  in  boil- 
ing water  for  8  minutes  for  kernel  fruit  and  for  10  minutes  for 
stone-fruit  or  berries.  The  jars  are  then  immediately  corked 
and  sealed. 

According  to  another  French  method,  the  flesh  of  the  fruit 
is  preserved  without  boiling.  Stone-fruits  and  berries  only 
can  be  used.  The  fruit  is  pressed  through  a,  hair-sieve  and 


PRESERVATION    OF    FRUIT.  437 

the  pulp  mixed  with  an  equal  weight  of  pulverized  sugar. 
The  mixture  is  then  brought  into  glass  bottles,  which  are 
corked  and  sealed.  This  fruit-pulp  keeps,  however,  only 
through  the  winter,  or  if  kept  in  a  cold  place  or  in  a  refrig- 
erator. 

The  following  method  gives  better  satisfaction  :  The  fruit, 
such  as  cherries,  berries,  plums,  peaches,  apricots,  etc.,  is, 
without  the  addition  of  water,  brought  into  wide-necked  glass 
jars  in  such  a  manner  that  a  layer  of  fruit  alternates  with 
a  layer  of  sugar,  the  top  layer  being  sugar.  The  jars  are  then 
tied  up  with  salicylated  parchment  paper,  placed  in  a  water- 
bath,  and  the  water  kept  boiling  for  15  to  30  minutes,  accord- 
ing to  the  variety  of  fruit,  small  fruit  requiring  less  time  than 
large,  and  berries  only  about  1G  minutes.  The  jars  are  then 
stored  in  a  cool,  dark  place.  For  closing  jars  with  narrow 
mouths  corks  are  preferable.  They  are  soaked  in  hot  salicy- 
lated water  and  sealed. 

Fruit  thus  preserved  retains  its  fresh,  natural  appearance 
and  keeps  for  a  considerable  time.  If  appearance  is,  however, 
of  secondary  consideration,  it  is  better  to  boil  the  fruit,  as  is 
done  with  kernel  fruit,  melons,  and  all  large  varieties.  The 
preparation  for  this  method  varies  according  to  the  nature  of 
the  fruit.  Apples  and  pears  must  be  peeled,  and,  if  not  too 
large,  only  cored,  otherwise  they  have  to  be  halved  or  quar- 
tered. Melons  are  peeled  and  cut  into  strips.  Quinces  are 
steamed  until  soft,  then  peeled  as  clean  as  possible,  quartered, 
and  the  cores  removed.  After  this  preparation  the  fruit  is 
brought  into  the  preserving  kettle  and  as  much  water  as  is 
necessary  for  boiling  added.  Boiling  should  be  done  very 
slowly  and  continued  until  the  fruit  commences  to  get  soft. 
It  should  not  be  boiled  too  soft,  but  only  sufficiently  so  to 
enable  it  to  absorb  the  sugar-liquor.  When  this  is  the  case 
the  fruit  is  taken  from  the  fire  and  strained,  and  with  the  liquor 
a  syrup  of  the  following  composition  is  prepared  :  For  each 
pound  of  fruit  take  one  pound  of  sugar  and  soak  it  in  J  pint 
of  the  liquor.  It  is  then  placed  upon  the  fire  and  the  resulting 


438  MANUFACTURE    OF    VINEGAR. 

syrup  skimmed.  When  it  boils  the  fruit  is  introduced  and 
slowly  boiled,  or  rather  simmered,  because  it  must  not  fall  to 
pieces,  for  five  to  ten  minutes,  according  to  its  softer  or  harder 
nature.  The  fruit  while  still  warm  is  then  brought  into  the 
jars,  in  which  no  vacuum  must  remain.  Hence  they  must  be 
filled  up  to  the  cork,  or  if  bladder  or  parchment  paper  is  used, 
for  closing  them  up  to  the  rim.  In  the  latter  case  it  is  advis- 
able to  place  upon  the  surface  a  close-fitting  piece  of  paper, 
previously  saturated  with  a  concentrated  solution  of  salicylic 
acid  in  rum.  Currants,  blackberries  and  grapes  are  sometimes 
preserved  in  their  natural  clusters.  They  are  first  washed  in 
fresh  water,  then  slowly  boiled  soft,  and  strained.  With  the 
liquor  a  syrup  of  the  previously  mentioned  composition  is 
prepared,  which  is  boiled  and  skimmed  and  poured  upon  the 
fruit  in  the  jars. 

Fine  table  pears  are  sometimes  preserved  in  the  following 
manner :  Eight  large  pears  are  placed  in  a  syrup  prepared 
from  6  ounces  of  sugar,  3  ounces  each  of  cloves  and  allspice, 
J  pint  of  water,  and  J  pint  of  port  wine  or  other  sweet  red 
wine.  In  this  syrup  they  are  boiled  very  slowly — as  much  as 
3  hours — until  soft,  and,  while  still  warm,  are  brought  to- 
gether with  the  syrup  into  jars,  which  are  treated  in  the 
manner  previously  described.  By  taking  equal  parts  of  pears 
and  of  fine  plums  a  very  beautiful  product  is  obtained. 

The  boiling  down  of  fruit  in  large  stoneware  pots  is  fre- 
quently accompanied  by  mishaps,  and  is  more  and  more  super- 
seded by  other  methods.  It  consists  in  dissolving  J  to  f  pound 
of  sugar  in  water  and  boiling  the  resulting  syrup  together  with 
the  fruit  until  the  whole  forms  a  jelly-like  mass.  While  still 
warm  the  pots,  which  must  be  full,  are  tied  up  with  bladder. 
A  piece  of  salicylated  paper  should  be  placed  upon  the  surface 
of  the  fruit  before  tying  up  the  pots. 

Preserving  in  Air-Tight  Cans. — This  method,  as  previously 
mentioned,  has  become  of  great  commercial  importance.  The 
number  of  factories,  briefly  termed  canneries,  has  largely  in- 
creased, and  not  a  few  of  them  employ  1,000  hands  during  the 


PRESERVATION    OF    FRUIT.  439 

fall.  Of  course  these  factories  do  not  limit  themselves  to  the 
canning  of  fruit,  as  otherwise  they  would  have  to  cease  opera- 
tions during  the  winter  months,  but  that  branch  of  the  busi- 
ness preponderates  over  all  others.  The  search  after  other 
suitable  material  is  constantly  more  extended,  and  the  trade- 
list  of  a  large  English  factory  now  contains  200  different 
articles ;  including  all  Southern  fruits,  a  portion  of  which 
is,  singularly  enough,  returned  in  this  state  to  the  tropics. 
The  American  trade-lists  embrace,  as  a  rule,  three  groups,  viz  : 

1.  Apples,    pears,  peaches,  apricots,   plums,    strawberries, 
raspberries,  blackberries,  currants,  cranberries,  whortleberries, 
nectarines,  grapes,  cherries,  quinces,    cocoanuts,   pineapples, 
marmalade,  jelly,  green  walnuts. 

2.  Peas,  beans,  beans  with  pork,  corn,  tomatoes,  asparagus, 
carrots,  onions,   pickles,  cauliflower,  horseradish,  mushrooms, 
catchups,  succotash,  plum-pudding,  sweet  potatoes. 

3.  All  kinds  of  poultry,  venison,  salmon,  lobster,  crawfish, 
oysters,  crabs,  beef,  mutton,  pork,  eels,  salt-water  fish,  ham, 
pig's  feet,  beef  tongue,  lamb's  tongue,  frog  legs,  mussels,  etc. 

All  the  varieties  of  fruit  named  in  the  first  group  being  not 
-equally  well  adapted  for  canning,  the  less  suitable  kinds  are 
only  used  in  small  quantities.  Plums  and  cherries  are  pre- 
ferably stoned,  as  well  as  peaches  and  apricots.  Heart-cherries, 
black  raspberries  and  whortleberries  are  the  best  suitable 
varieties  of  fruit  for  canning,  as  they  loose  their  agreeable 
taste  by  steaming.  Strawberries  also  become  somewhat  insip- 
id, but  red  raspberries  are  excellent  provided  they  are  canned 
as  soon  as  possible  after  being  gathered.  Blackberries  are  not 
quite  so  good  though  if,  brought  into  the  can  immediately 
when  plucked,  they  furnish  an  agreeable  dish.  Currants 
have  too  many  seeds,  and  are  better  used  for  jelly.  Black 
•currants  are  well  suited  for  canning,  and  in  this  state  are 
much  used  by  bakers  for  tarts.  Gooseberries  canned  before 
entirely  ripe  are  very  good.  Among  the  smaller  stone  fruit 
the  Mazard  cherry  has  few  superiors,  as  if  carefully  canned  it 
retains  its  shape,  color,  and  aroma  as  on  the  tree.  Most  plums 


440  MANUFACTURE    OF    VINEGAR. 

are  suitable  for  canning,  provided  they  are  stoned.  Among 
the  kernel  fruits  the  quince  occupies  the  first  rank,  as  it  is  the 
only  variety  of  fruit  which  gains  by  steaming.  Pears  are  very 
suitable  for  canning,  and  even  the  inferior  qualities  can  be 
used  for  the  purpose.  Apples,  however,  must  be  carefully 
selected,  and  only  sweet  varieties  with  firm  flesh  should  be 
used.  The  Siberian  crabapple  can  be  highly  recommended 
for  the  purpose.  • 

As  a  general  rule  fruit  for  canning  should  have  a  firm  flesh 
and  fine  aroma,  these  conditions  being  found  in  all  the  vari- 
eties preferred  by  the  packers  in  the  United  States,  whose 
canned  goods  can  be  found  in  every  large  city  of  the  world. 

Next  to  the  variety  of  fruit,  the  cans  are  of  the  greatest  im- 
portance. Much  has  been  said  and  written  in  regard  to  them, 
and  the  discussion  pro  and  con  will  very  likely  be  continued. 
Glass  jars  have  some  advantages.  They  are  comparatively 
cheap,  allow  of  an  inspection  of  their  contents  and  the  ready 
recognition  of  a  leak,  and  are  not  attacked  by  the  vegetable 
acid.  But,  nevertheless,  they  have  not  been  introduced  into 
general  use  because  they  are  liable  to  break,  and,  being  heavy, 
increase  the  cost  of  transportation,  and,  finally,  it  is  difficult  to 
close  them  air-tight.  The  sealing  of  a  bottle  with  a  narrow 
mouth  is  quite  a  different  thing  from  sealing  one  with  an  aper- 
ture three  inches  in  diameter.  It  may  do  for  pickles,  marmalade 
or  jelly,  but  for  preserved  fruits  which  are  to  be  transported 
long  distances  it  cannot  be  depended  on.  The  same  objections 
may  be  made  to  stoneware  jars,  which  possess  the  further  dis- 
advantage .that  their  contents  cannot  be  inspected  and  a  leak  is 
difficult  to  discover.  Nevertheless,  they  are  used  by  some  large 
English  factories  for  the  reason,  it  is  claimed,  of  keeping  their 
products  free  from  influences  deleterious  to  health.  To  facili- 
tate sealing,  the  jars  are  generally  small — of  about  one  pound 
capacity.  Tin  cans  have  many  defects,  but  their  use  is  very 
extensive,  and  in  the  United  States  they  are  almost  exclusively 
employed.  Complaint  has  been  frequently  made  that  the  use  of 
tin  cans  is  deleterious  to  health  because  the  tin  contains  lead, 


PRESERVATION    OF    FRUIT.  441 

which  is  dissolved  by  the  vegetable  acid  and  transferred  to  the 
fruit-s}Trup.  In  reply  it  has  been  said  that  only  the  inferior 
qualities  of  tin  contain  lead,  and  that  only  in  an  infinitesimal 
quantity  ;  but  it  cannot  be  denied  that  the  solder  may  readily 
become  injurious  to  health  and  in  cases  of  poison  investigated 
in  the  United  States  and  England  it  could  in  every  case  be 
shown  that  the  respective  cans  were  soldered  on  the  inside. 
The  time  is  very  likely  not  very  distant  when  such  soldering 
will  be  entirely  done  away  with.  To  completely  overcome  all 
complaints  against  solder,  as  well  as  against  a  content  of  lead 
in  the  tin,  cans  are  manufactured  which  are  provided  inside 
with  a  thin  coating  whereby  the  contents  are  protected  from 
contact  with  the  metal.  The  insoluble  constituent  of  this 
coating  consists  of  silicate  of  lirne  or  glass-powder  previously 
treated  with  hydrofluoric  acid,  while  the  soluble  constituent  is 
silicate  of  soda  or  of  potash.  Any  silicate  of  earthy  bases  or 
metals  may  be  used,  or  a  precipitated  gelatinous  silicate.  The 
alkali  is  fixed  or  removed  by  means  of  a  bath  containing  a 
dilute  solution  of  hydrofluosilicic  acid,  or  a  dilute  solution  with 
any  other  suitable  acid.  For  preparing  the  composition  mix 
the  soluble  with  the  insoluble  silicate.  The  tin  plates  are 
coated  with  this  mixture  by  means  of  a  brush,  or  dipped  in  a 
bath  of  it  and  then  dried  by  heat.  The  plates  thus  acquire  a 
glass-like  coating,  which  remains  fixed  no  matter  how  the 
plates  may  be  handled  and  worked.* 

In  the  canneries  in  the  United  States  the  cans  are  manufac- 
tured in  a  special  department,  and  the  division  of  labor  is 
carried  so  far  that  every  can  passes  through  eight  hands  before 
it  is  finished  ;  and  only  with  such  a  system  is  it  possible  to  turn 
out  large  quantities  in  an  incredibly  short  time.  This  far- 
reaching  division  of  labor  is,  however,  not  limited  to  this 
department  alone,  but  is  the  supreme  law  in  the  entire  estab- 
lishment. In  the  same  department  the  solder  is  cut  by  a 

*  In  this  country  some  packers  of  lobsters,  shrimps,  etc.,  line  the  cans  with 
parchment  paper. 


442  MANUFACTURE    OF    VINEGAR. 

machine  into  small  three-cornered  pieces.  Each  workman 
receives  a  certain  quantity  by  weight  of  solder  and  of  char- 
coal, with  which  he  is  expected  to  solder  a  certain  number  of 
-cans.  The  workmen  are  paid  by  the  piece,  and  each  solderer 
has  a  number  which  is  stamped  in  every  can  he  solders,  so 
that  those  which  prove  leaky  may  be  returned  to  him  for  re- 
pair. By  this  system  there  is  no  waste  of  material,  and  the 
leaky  cans  do  not  exceed  5  in  1,000. 

In  another  department  the  fruit  is  carefully  inspected  on  long 
tables ;  the  unsound  being  thrown  out,  and  the  sound  turned 
•over  to  the  peelers  and  stoners,  who  of  course  work  with  the 
most  improved  machines.  There  are  carriers  bringing  un- 
interruptedly fresh  fruit,  and  off-bearers  removing  and  sorting 
the  waste.  Nothing  is  thrown  away,  the  waste  being  used 
partially  in  the  manufacture  of  jelly  and  partially  in  distilling, 
-and  even  the  stones  are  utilized,  as  they  are  sold  either  to 
nurserymen  or  to  chemical  factories.  Other  workmen  are 
occupied  in  placing  the  peeled  and  stoned  fruit  in  the  cans, 
which  are  handed  over  to  boys,  who  place  them  upon  small 
trucks  running  upon  rails  and  transport  them  to  the  depart- 
ment where  the  filling  in  takes  place.  In  the  same  department 
the  syrup  of  sugar  and  water  is  prepared,  but  if  the  propor- 
tion of  composition  were  asked  a  different  answer  would  be 
received  in  every  cannery.  In  regard  to  this  point  every 
manufacturer  has  his  own  ideas,  which  also  extend  to  modifi- 
cations for  the  different  varieties  of  fruit.  All  manufacturers 
agree,  however,  that  the  best  quality  of  white  sugar  should  be 
used  for  light-colored  fruits,  and  light-brown  sugar  for  dark- 
colored,  and  that  the  syrup  must  be  perfectly  clear,  and  hence 
very  carefully  skimmed  in  boiling.  In  most  factories  the 
syrup  used  consists  of  1  Ib.  of  sugar  dissolved  in  1  pint  of 
water.  The  filling  of  the  cans  with  the  fruit  and  syrup,  the 
latter  being  generally  kept  warm,  is  effected  with  the  assist- 
ance of  scales,  so  that  each  can  has  exactly  the  weight  upon 
which  the  selling  price  is.  based.  The  caps,  previously  pro- 
vided with  a  hole  the  size  of  a  small  pea,  are  then  soldered 


PRESERVATION    OF    FRUIT.  443 

upon  the  cans.  The  hole  in  the  cap  serves  for  the  escape  of 
the  air  during,  the  succeeding  process. 

Different  kinds  of  apparatus  are  used  for  the  expulsion  of 
the  air  by  heating  the  cans.  In  large  factories  a  steam  retort 
is  used  which  resembles  in  shape  a  ship's  steam  boiler.  It  is 
provided  with  a  door  closing  air-tight,  and  is  divided  in  the 
•center  so  that  it  can  be  filled  either  half  or  entirely  with  steam, 
as  may  be  required.  The  cans  to  the  number  of  from  400  to 
600  are  placed  upon  trucks  which  run  upon  rails  leading  into 
the  retort.  Eight  such  trucks  can  be  introduced  at  one  time, 
so  that  is  is  possible  to  steam  from  30,000  to  40,000  cans  per 
day.  The  retort  being  filled,  the  door  is  closed  and  the  pipe 
•communicating  with  the  steam  boiler  opened.  The  cans  re- 
main in  the  retort  from  15  to  30  minutes,  according  to  the 
variety  of  the  fruit :  Berries  15  minutes,  stone-fruits  20,  apples 
and  pears  25,  quinces  and  tomatoes  30.  The  door  is  then 
opened,  and  after  the  steam  has  somewhat  dispersed  the  trucks 
are  quickly  pushed  to  the  tin-shop,  where  the  cap  holes  are 
soldered  up.  To  cleanse  the  cans  and  make  them  shiny  they 
are  next  put,  in  a  bath  of  soda  water  and  then  rinsed  off  with 
cold  fresh  water.  They  are  then  transferred  to  the  store  room, 
where  they  remain  standing  quietly  for  one  week,  when  they 
are  tested  by  striking  the  cap  of  each  a  short  sharp  blow  with 
a  wooden  hammer.  If  everything  is  in  order,  the  cap  sinks 
slowly  down,  but  if  it  is  elastic  and  jumps  back  the  can  is 
what  is  called  a  "swellhead,"  and  is  returned  to  the  tin-shop 
for  repairs  and  is  then  again  steamed.  The  perfect  cans  are 
labeled  and  packed  and  are  now  ready  for  market. 

Another  apparatus  which  can  be  highly  recommended  for 
small  factories  consists  of  a  round  iron  plate  resting  upon  a 
brick  base  about  one  foot  high.  Two  round  iron  rods  run  up 
opposite  to  each  other  from  the  edge  of  this  plate  and  serve 
as  a  support  for  a  movable  iron  cylinder  open  at  the  bottom 
and  closed  on  top.  Upon  the  iron  plate  the  cans  are  placed  in 
the  form  of  a  pyramid,  and  the  cylinder  is  then  drawn  down 
and  screwed  air-tight  to  the  plate.  A  pipe  communicating 


444  MANUFACTURE    OF    VINEGAR. 

with  the  steam-boiler  enters  the  cylinder,  and  as  soon  as  the 
latter  is  connected  with  the  plate  steam  is  admitted.  After  a 
certain  time,  which  corresponds  with  that  previously  given, 
the  steam  is  shut  off,  the  cylinder  pushed  up,  and  the  cans  re- 
moved, the  further  treatment  of  which  is  the  same  as  given 
above. 

In  some  factories  the  cans  are  still  heated,  according  to  the 
old  method,  in  boiling  water.  For  this  purpose  the  cans — 
100  at  a  time — are  placed  upon  an  iron  plate  attached  to  a 
steam-crane  and  submerged  for  15  to  20  minutes  in  boiling 
water  in  a  large  shallow  kettle.  In  this  case  the  caps,  are  not 
perforated,  but  soldered  down  air-tight.  A  workman  watches 
the  cans  while  they  remain  in  the  water  and  by  means  of  a 
tool  removes  those  from  which  small  bubbles  arise.  Such  cans 
being  not  air-tight  are  returned  to  the  tin-shop  for  repairs. 

The  rest  after  being  heated  are  also  brought  to  the  tin-shop, 
where  the  caps  are  perforated  with  a  hole  the  size  of  a  small 
pea,  which  is  again  soldered  up  after  the  escape  of  the  heated 
air. 

The  canning  of  tomatoes,  asparagus  and  other  vegetables 
is  effected  in  a  similar  manner  except  that  no  syrup  is  used. 
The  Appert  process  for  canning  meat  described  later  on  under 
"Preservation  of  Meat,  Fish  and  Eggs"  is  frequently  used  for 
the  more  expensive  kinds  of  vegetables,  such  as  asparagus, 
green  peas,  etc.,  glass  vessels  being  generally  used.  The  vege- 
tables are  first  cleaned  and  trimmed,  and  are  then  covered 
with  water  in  the  vessels,  with  or  without  a  little  salt.  Sticks 
of  asparagus,  or  whole  beans,  are  stood  on  end.  The  vessels 
are  now  lightly  corked  and  boiled  in  a  bath  of  concentrated 
brine,  in  which  they  are  stood  upright  as  fully  immersed  as 
possible.  The  bath  is  heated  very  slowly  to  avoid  cracking 
the  glass.  It  should  take  about  two  hours  to  bring  the  tem- 
perature to  212°  F.  The  brine  is  then  brought  to  the  boil, 
whereupon  the  contents  of  the  glasses  will  also  boil.  After 
they  have  been  boiled  for  about  ten  minutes,  the  bath  is  al- 
lowed to  cool  to  about  140°  F.,  and  the  corks  are  driven  in 


PRESERVATION    OF    FRUIT.  445 

tightly.  Fused  paraffin  is  then  poured  over  them,  and  when 
the  bath  is  quite  cold,  the  glasses  are  taken  out.  The  vege- 
tables will  then  keep  for  as  long  as  the  vessels  are  unopened, 
for  all  ferments  in  them  have  been  destroyed,  and  the  para- 
fined  cork  prevents  any  more  from  getting  access  to  them. 
The  paraffin  should  come  flush  with  the  edge  of  the  jar,  and 
should  be  tied  over  with  vegetable  parchment  to  prevent  it 
from  cracking  and  flaking  off.  The  top  of  the  cork  should  be 
rough  so  that  it  may  adhere  better  to  the  paraffin. 

As  the  canning  of  tomatoes  may  serve  as  a  type  for  all  other 
vegetables  a  description  of  the  process,  for  which  we  are  in- 
debted to  Mr.  Richard  T.  Starr,  of  Salem,  N.  J.  is  here  given. 

The  tomato  was  for  many  years  found  only  in  hot-houses 
and  conservatories  of  the  rich.  It  was  known  as  the  love- 
apple  and  considered  a  curiosity.  Our  ancestors  had  no  idea 
that  this  small  red  berry,  for  such  was  about  its  size,  would 
ever,  even  under  careful  cultivation,  become  of  mammoth 
size  and  form  one  of  our  most  important  articles  of  food.  But 
such  is  actually  the  case  to-day.  The  exact  time  when  the 
now  great  industry  of  canning  this  vegetable  commenced  can- 
not be  established  with  any  certainty.  The  taste  for  the 
tomato  seems  to  be  an  acquired  one,  and  for  years  the  industry 
struggled  in  its  infancy  until  the  breaking-out  of  the  War  of 
the  Rebellion  caused  a  demand  that  rapidly  grew  into  gigantic 
proportions,  and  to-day  finds  the  tomato-canning  industry 
employing  an  army  of  men,  women  and  children,  while 
millions  of  dollars  are  invested  in  the  payment  of  labor  and 
the  erection  of  plants. 

In  order  that  our  readers  may  have  a  clear  idea  of  the  busi- 
ness we  will  commence  with  the  beginning.  Having  made  up 
his  mind  to  engage  in  it  on  an  average  scale,  the  packer  will 
first  find  a  suitable  plot  of  ground,  on  a  navigable  stream, 
if  possible.  Having  secured  this,  the  next  thing  is  the  erec- 
tion of  the  buildings  ;  these  are  generally  one  story  in  height 
and  as  large  and  roomy  as  the  capital  will  warrant.  The 
next  step  is  to  secure  the  requisite  supply  of  fruit,  and  for 


446  MANUFACTURE    OF    VINEGAR. 

this  purpose  the  farmers  are  drawn  on  and  contracts  entered 
into  with  them  in  which  the  packer  agrees  to  take  the  entire 
marketable  product  of  a  certain  number  of  acres,  or  else  to  take 
so  many  tons.  These  contracts  are  generally  made  about  the 
first  of  the  year,  and  as  soon  as  the  sun  drives  the  frost  from 
the  ground  the  farmer  prepares  his  beds  and  sows  his  seed. 
While  the  latter  is  growing,  the  land  which  is  to  be  planted  is 
heavily  manured  and  plowed  and  carefully  worked  until  it  be- 
comes mellow,  and  then  hills  about  four  feet  apart  are  made, 
and  into  each  one  is  put  a  small  quantity  of  compost  of  phos- 
phates. The  tomato  plants,  having  by  this  time  grown  to  the 
height  of  6  or  8  inches,  are  taken  from  the  beds,  and  on  a 
cloudy  day,  or  the  latter  part  of  a  bright  day,  transplanted 
and  tended  about  as  other  growing  crops.  With  a  favorable 
season  the  farmer  should  commence  delivering  to  the  factory 
about  the  middle  of  August. 

The  arrangement  of  a  canning  factory  is,  of  course,  a  matter 
of  taste,  but  the  most  complete,  in  our  opinion,  is  one  where 
everything  moves  in  a  straight  line,  and  in  which  none  of  the 
help  are  obliged  to  interfere  with  one  another.  The  first  thing 
to  be  done  with  a  load  of  tomatoes  is,  of  course,  to  weigh 
them,  and  for  this  purpose  platform  scales  are  built  at  an  end 
door  and  the  wagons  driven  on  them.  After  being  weighed 
the  tomatoes  are  handed  over  to  the  scalder.  Tomatoes  arriv- 
ing in  all  kinds  of  weather  and  conditions  must,  of  course,  not 
•only  be  washed  but  scalded,  so  as  to  thoroughly  loosen  the  skin 
from  the  pulp;  and  to  do  this  quickly  and  properly,  a  heavy 
box  of  white  pine  is  fitted  with  both  steam  and  water  pipes,  and 
attached  to  it  is  an  iron  cradle  swinging  on  hinges  and  raised 
and  lowered  by  a  wheel  and  pulley  suspended  above.  On  the 
back  of  this  is  placed  a  box,  and  as  the  farmer  hands  off  his 
baskets  they  are  emptied  into  this  box,  and  at  the  command 
of  the  man  at  the  rope,  who  is  called  the  "  scalder,"  they  are 
dumped  into  the  boiling  water  beneath.  A  few  seconds  suffice 
to  clean  and  scald  them  ;  the  cradle  is  then  raised  and  the 
tomatoes  are  poured  into  kettles  set  in  front  of  the  scalder  to 
receive  them. 


PRESERVATION    OF    FRUIT.  447" 

While  this  has  been  going  on  a  group  of  women  and  girls 
have  been  filing  into  the  factory  and  seating  themselves  along 
the  trays  that  are  to  receive  the  tomatoes  from  the  scalder. 
These  trays  are  of  different  construction,  but  are  similar  as  re- 
gards length,  breadth  and  depth,  the  only  difference  being  in, 
the  various  ways  of  getting  rid  of  the  water  and  juice.  This- 
is  generally  done  by  making  a  slat  frame  fit  in  the  bottom  and> 
over  a  trough  fastened  under  the  tray.  This  leads  to  a  drain, 
which  carries  it  to  the  creek  or  wherever  else  it  is  to  go.  At 
each  tray  are  from  ten  to  twelve  women,  each  of  them  furnished 
by  the  packer  with  a  bowl  and  knife,  and  provided  at  their  own 
expense  with  a  neat  water-proof  apron.  The  tomatoes  are- 
dumped  from  the  kettles  in  front  of  them,  and  they  remove 
rapidly  the  already  loosened  skins  and  cores  and  deposit  the 
prepared  fruit  in  a  bucket  sitting  beside  them.  They  become 
so  efficient  that  a  smart,  active  woman  will  frequently  skin  from, 
40  to  60  buckets  a  day,  and  as  they  receive  4  cents  per  bucket 
it  will  be  seen  they  make  fair  wages.  Standing  just  beyond1 
the  women  are  the  machines  which  fill  the  cans.  To  describe- 
them  would  be  impossible,  there  being  so  many  shapes  and 
many  makes.  Some  are  very  good,  some  very  poor,  every 
man  thinks  his  the  best,  and  so  it  goes  ;  but  in  one  respect  they 
all  agree :  they  have  a  hopper  into  which  the  fruit  is  poured* 
from  the  buckets,  and  all  have  the  plunger  which  forces  the 
fruit  into  the  cans  ;  the  treadles  of  some  of  them  are  moved  by 
hand  and  some  by  steam.  The  machines  rapidly  fill  can  after 
can,  which  are  then  set  on  the  "  filling  table  "and  receive 
"  top  them  off,"  or  in  other  words  the  fruit  is  cleared  away 
from  the  top  of  the  can  so  that  the  solder  used  in  capping: 
them  will  not  become  chilled.  They  are  then  placed  in  trays- 
each  holding  either  10  or  12  cans  and  removed  to  the  "  wiping 
table,"  where  everything  is  cleared  from  the  top,  wiped  dry 
with  sponges,  and  the  cap  placed  over  the  opening.  The 
"  cappers "  stand  directly  in  front  of  the  wiping  table,  and 
each  one  has  his  own  fire-pot,  irons,  files,  and  everything  he 
uses  before  him.  Taking  the  tray,  he  rapidly  applies  by 


448  MANUFACTURE    OP    VINEGAJR. 

means  of  a  small  brush  the  acid  or  flux  necessary  to  make  the 
solder  flow  freely  around  the  cap,  and  then  with  the  iron  melts 
the  solder  and  puts  it  in  the  groove.  The  can  is  then  vented 
and  is  ready  for  the  "bath."  The  baths,  except  in  size,  are 
-constructed  similarly  to  the  scalder,  and  a  thin  cedar  cover 
fits  over  each  one.  The  cans  are  placed  in  wire  or  iron  crates, 
lowered  into  the  boiling  water,  and  allowed  to  remain  as  long 
as  necessary  to  cook  them.  The  time  of  working  varies  in 
the  different  factories,  but  all  the  way  from  30  to  50  minutes 
is  required.  They  are  then  taken  from  the  bath  and  placed 
on  a  slat-floor,  where  the  air  can  pass  through  them,  and  when 
they  are  cold  are  "  tested,"  generally  by  striking  them  with 
an  awl.  The  testers  become  so  expert  that  they  can  instantly 
•detect  by  the  sound  an  imperfect  or  leaking  can ;  these  are 
thrown  out,  mended,  re-pressed,  and  put  back  in  the  pile. 
The  cans  are  now  ready  for  the  next  thing,  which  is  labeling. 

Labeling  is  done  in  different  ways,  and  some  canners  with 
an  idea  of  saving  labor  employ  devices  which  are  not  only 
hard  on  the  young  girls  who  do  the  work,  but  which  often  re- 
sult in  much  confusion  and  poor  work.  The  best  method  is 
to  divide  the  help  into  parties  of  five,  one  girl  sitting  on  one 
side  of  the  table  with  paste-pan,  brush,  and  labels  and  the 
other  four  opposite  her.  The  one  girl,  if  quick  and  active, 
will  paste  the  ends  of  the  labels  as  fast  as  the  other  four  can 
put  them  on  the  cans.  The  table  is  of  course  alongside  the 
pile  of  cans,  and  two  smart  boys  will  place  the  cans  on  the 
table.  As  a  girl  labels  a  can  she  pushes  it  from  her,  when  it 
is  taken  by  the  boxer,  put  in  the  box,  and  nailed  up.  This 
mode  is  simple  and  effective,  and  as  the  gang  will  label  from 
700  to  900  cases  in  a  day  the  work  progresses  rapidly. 

In  many  of  the  larger  factories  patent  processing  kettles, 
capping  irons,  and  improved  machinery  are  used,  but  as  the 
result  is,  of  course,  the  same,  and  they  do  not  affect  the  mode 
of  packing,  it  is  not  thought  necessary  to  enter  into  any  de- 
scription of  them. 

In  the  foregoing  an  outline  of  the  packing  process  has  been 


PRESERVATION    OF    FRUIT.  449 

given,  but  nothing  has  been  said  of  the  many  trials  and  vexa- 
tions of  a  canner's  life.  If  everything  went  always  smoothly, 
it  would  be  as  pleasant  as  any  other  business,  but  it  does  not. 
The  canner  will  early  in  the  season  employ  his  hands  and  com- 
mence in  a  small  way.  He  may  start  and  run  only  two  or 
three  hours,  and  for  that  length  of  time  boilers  will  have  to  be 
fired  up,  help  got  together,  and  at  the  close  the  factory  cleaned 
the  same  as  if  he  had  run  the  day  out.  Then,  as  the  crop 
rapidly  matures,  work  becomes  heavier,  and  at  last  the  inev- 
itable "glut"  commences,  and  he  finds  the  products  of  400  or 
500  acres  of  perishable  fruit  at  his  doors,  maybe  50  wagons, 
each  owned  by  an  impatient  farmer  standing  in  the  street  wait- 
ing his  turn  to  unload.  That  is  the  time  he  has  need  of  nerve  ; 
help  must  be  secured,  everything  and  everybody  pushed  to 
their  utmost  endurance,  and  from  early  morning  until  way 
into  the  night,  day  after  day,  the  week  goes  on  ;  help  succumbs, 
and  machinery  breaks,  but  the  factory  must  move  in  storm 
and  in  sunshine.  The  work  must  go  on,  and  at  last  the  agony 
is  over,  and  the  crop  coming  in  again  gradually  gives  a  little 
relief  to  the  overworked  people. 

It  would  be  an  impossibility  to  correctly  state  the  amount 
of  capital  invested  or  the  number  of  persons  employed  in  the 
industry.  The  States  of  New  Jersey,  Maryland  and  Delaware 
pack  a  large  proportion  of  the  goods,  the  late  falls  and  the 
nature  of  the  soil  being  particularly  well  adapted  for  raising 
tomatoes. 

In  connection  with  the  canning  of  tomatoes  it  may  be  of 
interest  to  our  readers  to  give  the  preparation  of 

Catchups. — Under  the  name  of  catchup  or  catsup  a  thickly- 
fluid  sauce  comes  into  commerce,  which  is  used  as  a  condiment 
with  meat,  and  the  preparation  of  which  has  become  of  some 
importance.  Everywhere  where  Anglo-Saxons  reside  catchup 
is  found,  though  it  has  also  been  introduced  on  the  continent 
of  Europe  and  in  the  tropics.  The  varieties  most  liked  are 
tomato  and  walnut  catchups,  and  immense  quantities  of  them 
are  manufactured  in  the  American  canning  establishments. 
29 


450  MANUFACTURE    OF    VINEGAR. 

The  mode  of  preparation  is  so  simple  that  it  can  be  introduced 
into  every  kitchen. 

Tomato  Catchup. — The  receipts  for  making  this  favorite 
catchup  are  innumerable,  and  should  those  of  every  packer 
and  housewife  in  the  land  be  taken  and  put  together  they 
would  make  a  good-sized  volume. 

In  some  factories  where  the  tomatoes  are  peeled  and  either 
canned  or  made  into  some  whole  tomato  product,  such  as 
chili  sauce,  the  trimmings  are  made  into  catchup,  all  decayed 
portions  being  rejected.  The  trimmings  are  sometimes  run 
to  a  chopper  before  going  to  the  pulping  machine.  In  some 
plants  the  stock  is  cooked  before  running  it  into  the  pulping 
machine,  while  in  others  the  pulp  is  made  from  raw  tomatoes. 
It  makes  little  difference  which  method  is  used,  so  there  is  no 
material  delay  between  the  time  of  pulping  and  the  using  of 
the  pulp.  At  some  places  the  pulp  is  run  as  fast  as  made 
into  a  single  vat  and  drawn  out  from  the  same  during  the 
day  as  needed.  In  this  way  the  pulp  is  run  with  some  that 
may  have  been  in  the  vat  for  several  hours,  and  there  is  a 
possibility  of  spoilage  to  begin  with  and  consequently  of  some 
injury  to  the  product.  If  the  pulp  is  to  be  stored  at  all,  a  set 
of  smaller  vats  is  preferable,  so  that  each  vat  as  it  is  emptied 
can  be  cleaned  out  before  a  new  lot  is  run  in,  thus  checking 
any  fermentation  that  might  result  due  to  the  storing  of  the 
pulp  in  the  same  vat  throughout  the  day's  run. 

The  pulp  obtained  from  the  fruit,  in  making  catchup  is 
generally  concentrated  to  about  50  or  25  per  cent,  of  the  orig- 
inal volume  by  boiling  or  the  gravity  method,  the  latter  being 
employed  by  the  majority  of  the  plants  making  trimming 
pulp.  At  some  plants  it  is  customary  to  process  the  catchup 
after  bottling  while  others  find  it  unnecessary. 

No  receipt  can  be  given  that  will  suit  all  in  regard  to  the 
amount  of  the  different  condiments  to  be  used  as  each  person 
has  ideas  of  his  own,  but  all  catchup  should  be  made  hotter 
than  desired,  as  it  will  undoubtedly  lose  some  of  its  strength 
when  it  becomes  cold.  The  best  of  spices  and  vinegar  should 


PRESERVATION    OF    FRUIT.  451 

be  used  and  every  vessel  into  which  it  is  put  should  be  scrup- 
ulously clean  and  free  from  any  mold  or  dust.  Seal  the 
bottles  carefully,  and  if  you  have  them  thoroughly  air-tight, 
the  catchup  will  improve  with  age. 

Below  a  few  receipts  for  making  catchup  on  a  small  scale 
are  given. 

I.  Take  15  quarts  of  thoroughly  ripe  tomatoes,  4  tablespoon- 
fuls  each  of  black  pepper,  salt,  and  allspice,  8  red  peppers,  and 
3  teaspoonfuls  of  mustard.     The  pepper  and  allspice  must  be 
ground  fine  and   the  whole  boiled  slowly  3  to  4  hours;  then 
pass  all  through  a  fine  sieve  and  when  cold  put  it  in  bottles, 
which  must  be  immediately  sealed. 

II.  Boil  4  quarts  of  tomatoes  together  with  2  quarts  of  vine- 
gar, 2  tablespoonfuls  of  red  pepper,  4  tablespoonfuls  of  black 
pepper,  1  tablespoonful  of  cloves,  1  teaspoonful  of  salt,  and  1 
ground  nutmeg,  to  a  thick  paste.     Strain  through  a  coarse- 
meshed  sieve  and  sweeten  the  sauce  obtained  with  J  Ib.  of 
sugar.     Fill  in  bottles  and  shake  once  every  day  for  a  week. 

III.  Cut  up  perfectly  ripe  tomatoes  and  place  them  upon 
the  fire  until  they  commence  to  bubble.     Then  take  them 
from  the  fire,  and  when  cool  rub  them  with  the  hand  through 
a  hair-sieve  and  season  according  to  the  following  propor- 
tions :  For  each  quart  of  sauce  add  1  teaspoonful  of  ground 
allspice,  1  teaspoonful  of  ground  cloves,  1  tablespoonful  of  salt, 
and  1  quart  of  wine-vinegar.     Stir  the  whole  thoroughly  to- 
gether, replace  it  upon  the  fire,  and  boil  for  one  hour,  with 
constant  stirring.     When  cool  put  the  catchup  in  bottles  and 
seal  immediately. 

Walnut  Catchup. — I.  In  June,  when  the  walnuts  are  still- 
soft,  take  10  dozen  of  them,  and  after  crushing  pour  over 
them  2  quarts  of 'wine-vinegar,  add  the  following  spices,  all 
ground  :  2  tablespoonfuls  of  black  pepper,  1 J  oz.  of  nutmeg, 
40  cloves,  J  oz.  of  ginger,  J  oz.  of  mace,  and  boil  the  whole 
i  hour,  stirring  constantly.  When  cold  strain  through  a 
hair-sieve  and  put  the  catchup  in  bottles. 

II.  Crush  about  10  dozen  of  young,  soft  walnuts,  sprinkle 


452  MANUFACTURE    OF    VINEGAR. 

{  lb.  of  sugar  over  them,  and  then  add  1  quart  of  vinegar. 
Let  the  whole  stand  six  weeks,  stirring  frequently.  Then 
strain  through  a  bag,  with  constant  pressing  with  the  hand. 
Pour  1  pint  of  vinegar  over  the  residue,  let  it  stand  over  night, 
and  strain  again  through  the  bag.  Combine  the  fluid  with 
that  previously  obtained  and  season  with  the  following  spices, 
all  ground  :  1}  oz.  of  black  pepper,  \  oz.  of  nutmeg,  J  oz.  of 
ginger,  \  oz.  of  mace,  and  40  cloves.  Then  boil  J  hour,  strain 
through  a  hair-sieve  and  bottle. 

Cucumber  Catchup. — Thoroughly  ripe  cucumbers,  before  turn- 
ing yellow  are  peeled  and  grated  upon  a  coarse  grater.  This 
paste  is  brought  into  a  colander  to  allow  the  juice  to  run  off, 
then  pressed  through  a  coarse  hair-sieve  to  remove  the  seeds, 
and  finally  brought  into  small,  wide-mouthed  bottles,  which 
are  rilled  j  full.  The  remaining  space  is  filled  up  with  good 
wine-vinegar.  This  catchup  has  the  taste  and  odor  of  fresh 
cucumbers,  and  is  used  as  a  condiment  with  meat.  Before 
bringing  it  to  the  table  it  is  seasoned  to  taste  with  salt  and 
pepper. 

Horseradish  Catchup. — The  mode  of  preparation  is  the  same 
as  for  the  preceding,  putting  the  grated  mass  in  a  colander  and 
straining  through  a  hair-sieve  being,  however,  not  necessary. 
Both  varieties  of  catchup  must  be  immediately  corked,  sealed, 
and  kept  in  a  cool  place.  Within  the  last  few  years  both  have 
been  prepared  on  a  large  scale  in  the  United  States  and  Eng- 
land, and  have  become  an  article  of  export.  They  are  packed 
in  small,  wide-mouthed  bottles,  sealed,  and  provided  with 
gaily-colored  labels.  Some  English  factories  use  small  earth- 
enware pots  of  a  cream  color,  closed  with  corks  over  which  is 
tied  strong  colored  paper.  The  pots  are  very  good,  but  the 
manner  of  closing  them  is  not ;  the  corks  should  be  sealed. 

Currant  Catchup. — Heat  nearly  to  the  boiling  point,  with 
constant  stirring,  4  Ibs.  of  thoroughly  ripe  currants  together 
with  1J  Ibs.  of  sugar.  Then  add  1  tablespoonful  each  of  cin- 
namon, salt,  cloves,  and  pepper — all  finely  pulverized — and  1 
quart  of  vinegar.  Boil  the  mixture  one  hour  and  then  treat 
in  the  same  manner  as  tomato  catchup. 


PRESERVATION    OF    FRUIT.  453 

Gooseberry  CatcJiup. — This  product  also  comes  into  commerce 
under  the  name  of  "  spiced  gooseberries."  It  is  an  excellent 
condiment  with  roast  fowl.  Take  6  quarts  of  gooseberries, 
ripe  or  unripe  as  may  be  desired,  and  carefully  remove  the 
steins  and  pistils.  Then  bring  them  into  a  kettle,  and  after 
pouring  some  water  and  scattering  5  Ibs.  of  pulverized  sugar 
'over  them,  boil  for  1J  hours.  After  boiling  1J  hours  add  4 
Ibs.  more  of  sugar  and  1  tablespoonful  each  of  allspice,  cloves 
and  cinnamon.  The  catchup  is  not  strained,  but  brought  at 
once  and  while  warm  into  wide-mouthed  bottles  or  pots,  which 
are  immediately  corked  and  sealed.  It  is  advisable  before 
closing  the  bottles  to  lay  a  closely-fitting  piece  of  salicylated 
paper  upon  the  surface  of  the  catchup.  The  bottles  should  be 
kept  in  a  cool  place. 

It  need  scarcely  be  remarked  that  catchup  can  be  prepared 
not  only  from  the  above,  but  from  all  varieties  of  fruit,  and  it 
is  only  necessary  to  take  one  of  the  above  receipts  as  a  type. 
But,  with  few  exceptions,  those  given  are  the  only  catchups 
prepared  on  a  large  scale  and  brought  into  commerce. 

Another  subject  which  may  be  referred  to  in  connection 
with  the  preservation  of  fruit  is  the  preparation  of 

Fruit-butter,  Marmalade  and  Jelly — Fruit-butter. — The  manu- 
facture of  apple-butter,  which  may  serve  as  a  type  of  that  of 
all  other  fruit-butters,  is  effected  as  follows  :  Fill  the  boiler 
two-thirds  full  with  the  juice  of  sweet  and  bitter-sweet  apples 
in  about  the  same  proportion  as  given  for  the  manufacture  of 
cider.  The  other  third  of  the  boiler  is  filled  up  with  slices  of 
ripe,  juicy  apples,  and  the  mixture  boiled,  with  frequent  stir- 
ring. When  the  slices  of  apples  are  so  soft  that  they  com- 
mence to  fall  to  pieces,  they  are  carefully  removed  from  the 
boiler  by  means  of  a  skimmer,  care  being  had  to  allow  the 
juice  to  run  off.  The  same  quantity  of  fresh  slices  of  apples 
is  then  brought  into  the  juice  and  boiled  in  the  same  manner 
as  the  preceding.  When  these  have  acquired  the  necessary 
degree  of  softness,  the  entire  contents  of  the  kettle,  together 
with  the  slices  of  apples  previously  boiled,  are  brought  into  a 


454  MANUFACTURE  OF  VINEGAR. 

stoneware  pot  and  allowed  to  stand  covered  for  12  hours. 
The  mass  is  then  replaced  upon  the  fire  and  boiled,  with 
constant  stirring,  until  it  has  acquired  the  consistency  of  soft 
soap.  If  desired,  it  can  at  the  same  time  be  seasoned  with 
cinnamon,  nutmeg,  etc.  To  prevent  scorching,  the  second 
boiling  is  effected  in  vessels  standing  in  boiling  water. 

In  the  same  manner  fruit-butter  can  be  prepared  from  all 
varieties  of  fruit,  pear  or  apple  juice  forming,  however,  always 
the  boiling  liquor.  Apple  and  peach  butters  are  commercially 
of  the  greatest  importance,  though  butter  of  quinces,  pears, 
blackberries,  cherries,  plums  and  cranberries  is  also  manu- 
factured on  a  large  scale.  Whortleberries,  which  grow  in 
enormous  quantities  in  some  parts  of  the  country,  might  also 
form  an  excellent  material  for  this  product.  In  the  foregoing 
only  the  varieties  are  mentioned  which  are  manufactured  on  a 
large  scale  by  American  and  English  factories  that  chiefly  con- 
trol the  trade  in  fruit-butters,  but  these  do  not  by  any  means 
exhaust  the  list.  Green  gages  can,  for  instance,  be  highly 
recommended  for  the  purpose. 

The  excellent  product  brought  from  France  into  commerce 
under  the  name  of  raisine  is  prepared  in  the  above  manner  by 
slowly  boiling  sliced  apples  and  pears  in  unfermented  grape- 
juice. 

Fruit-butter  is  packed  in  wooden  buckets  of  5  or  10  Ibs. 
capacity  and  in  stoneware  jars.  Tin  cans  holding  2  Ibs.  are 
also  sometimes  used,  but  they  are  not  liked.  The  buckets 
are  slightly  conical  towards  the  top  and  are  provided  with  a 
wire  handle.  Resinous  wood  should  not  be  used  in  their 
construction,  as  it  would  impart  an  odor  to  the  fruit-butter. 
The  buckets  are  filled  up  to  the  edge,  and  a  closely  fitting 
round  piece  of  paper  previously  saturated  with  concentrated 
solution  of  salicylic  acid  in  whiskey  is  laid  on  top  of  the  butter. 
The  tight-fitting  lid  is  placed  upon  the  bucket  without  being 
sealed  or  otherwise  closed.  A  large  lable  occupying  the  space 
between  the  lower  and  upper  hoops  finishes  the  packing. 

Marmalade. — The  same  product  is  sometimes  called    mar- 


PRESERVATION    OF    FRUIT.  455 

malade  and  sometimes  jam.  The  French  prepare  only  mar- 
malade, while  the  Englishman  brings  the  same  product  into 
commerce  as  jam  or  as  marmalade,  just  as  it  may  suit  him 
best,  and  the  German  is  not  much  better.  The  term  marma- 
lade was  originally  applied  to  a  jam  prepared  from  quinces, 
it  deing  derived  from  marmelo,  the  Portuguese  word  for  quince. 
The  term  was  gradually  given  to  all  jams  in  order  to  give 
them  a  more  distinguished  character,  and  this  has  led  to  a 
confusion  of  terms  which  sometimes  extends  even  to  jelly. 
There  is,  however,  a  wide  distinction  :  Marmalade  or  jam  is 
prepared  from  the  pulp  of  fruit  and  jelly  from  the  juice,  while 
fruit-butter,  as  above  indicated,  is  a  blending  of  both  with  the 
omission  of  sugar. 

For  the  manufacture  of  marmalade  on  a  large  scale  all  the 
rules  and  receipts  can  be  condensed  as  follows  :  The  fruit  must 
be  of  excellent  quality,  entirely  free  from  blemishes  and 
washed  perfectly  clean.  Kernel  fruit  is  peeled,  quartered  and 
freed  from  the  cores ;  peaches  are  also  peeled,  halved,  and 
stoned  ;  other  stone-fruit  is  only  stoned  and  halved,  while 
berries  are  carefully  freed  from  the  stems.  Melons  and  pump- 
kins are  peeled  and  cut  into  small  pieces.  Rhubarb  should 
not  be  washed  but  rubbed  with  a  moist  cloth  and  be  then  cut 
into  small  pieces.  Tomatoes  are  to  be  peeled  which  is  facili- 
tated by  previously  placing  them  for  one  minute  in  hot  water. 
Being  thus  prepared  the  fruit  is  brought  into  a  copper  kettle 
and  as  much  water  as  is  required  for  boiling-  added.  While 
the  fruit  is  boiling,  weigh  off  as  many  pounds  of  white  sugar 
as  there  is  fruit,  soak  it  in  water,  boil  and  skim  carefully. 
The  fruit  should  be  boiled  quickly,  and  when  perfectly  soft  is 
allowed  to  cool  off  somewhat  and  then  rubbed  through  a  wide- 
meshed  hair-sieve.  The  mass  passing  through  the  sieve  is 
combined  with  the  sugar  and  replaced  upon  the  fire.  The 
whole  is  then  boiled  with  constant  stirring,  to  the  required 
consistency.  The  latter  is  tested  by  taking  a  small  sample 
with  a  wooden  or  bone  spoon — nothing  else  should  be  used — 
and  if  it  draws  threads  between  the  fingers  the  boiler  is  removed 


456  MANUFACTURE    OF    VINEGAR. 

from  the  fire.  The  marmalade  is  then  brought  into  straight 
jars,  and  after  laying  a  piece  of  salicylated  paper  on  top,  the 
jars  are  iied  up  with  white  parchment  paper  or  sometimes 
covered  with  a  glass  cover  and  labeled.  It  may  be  remarked 
that  in  the  last  stage  of  boiling  the  marmalade  is  sometimes 
flavored,  which  is  generally  effected  by  stirring  in  lemon  juice, 
cinnamon,  and  nutmeg  according  to  taste.  The  liquor  ob- 
tained by  boiling  crushed  kernels  of  plums  or  peaches  is  also 
often  at  the  same  time  added  as  flavoring.  Frequently  the 
sugar  is  not  treated  as  stated  above,  but  added  in  the  form  of 
powder. 

The  quantity  of  sugar  has  above  been  given  in  the  propor- 
tion of  1  Ib.  to  1  Ib.  of  fruit.  Though  this  is  the  customary 
rule,  many  manufacturers  use  only  j  Ib.  of  sugar,  a  method 
which  can  be  highly  recommended.  In  fact  there  is  frequently 
a  perfect  waste  as  regards  the  addition  of  sugar,  some  adding 
even  1J  Ibs.  of  it  to  the  pound,  whereby  the  taste  of  fruit  is 
entirely  lost  and  the  product,  on  account  of  its  sweetness,  to 
many  becomes  repugnant.  It  may  be  laid  down  as  a  rule  that 
in  all  fruit  boiling  no  more  sugar  than  is  absolutely  necessary 
should  be  used.  The  secret  of  the  great  reputation  the  prod- 
ucts of  the  principal  American  factories  enjoy  in  all  portions  of 
the  world  is  simply  due  to  the  fact  that  they  use  as  little  sugar 
as  possible,  whereby  the  products  are  rendered  not  only 
cheaper,  but  they  retain  their  natural  fruit  taste,  and  that  is 
what  the  consumer  desires,  and  not  a  sugary  paste  having  only 
the  color  of  the  preserved  fruit.  The  durability  of  the  product 
need  not  necessarily  suffer  if  due  care  is  exercised  in  its  prep- 
aration. Marmalade  should  not  be  made,  as  it  is  only  too  fre- 
quently done,  from  fruit  which  has  been  gathered  for  several 
days  and  shows  signs  of  decay.  Fruit  not  over-ripe  and  freshly 
gathered  should  be  used  and  the  boiling  finished  as  quickly  as 
possible.  By  then  rinsing  the  jars  with  salicylated  water  and 
covering  the  marmalade  with  a  piece  of  paper  saturated  with 
concentrated  solution  of  salicylic  acid  or  with  alcohol,  }  Ib.  of 
sugar  to  1  Ib.  of  fruit  will  be  ample,  and  even  J  Ib.  with  sweet 


PRESERVATION    OF    FRUIT.  457 

fruits  such  as  pears,  raspberries,  etc.  Independently  of  the 
saving  of  sugar,  such  marmalade  will  give  better  satisfaction 
than  an  article  twice  as  sweet,  and  will  keep  well  in  a  dark, 
cool  place. 

Some  manufacturers  use  glucose  in  large  quantities  in  mak- 
ing jams  and  marmalades.  Some  think  it  cheapens  the  bulk 
and  causes  it  to  congeal,  while  others  claim  that  it  causes  the 
preserve  to  be  heavy,  syrupy  and  stringy. 

In  some  factories  apple  pulp  is  used  as  foundation  for  cheap 
jams,  the  proportion  of  it  employed  varying  according  to  what 
fruit  is  available.  It  is  made  by  filling  the  steam-pan  full  of 
good  cooking  apples  and,  after  turning  on  the  steam,  boiling 
them  for  20  to  30  minutes.  It  is  advisable  to  put  some  heavy 
weight  on  the  cover  of  the  steam-pan  before  turning  on  the 
steam  to  prevent  it  from  being  blown  off.  When  boiling  is 
finished  take  off  the  cover,  and  with  a  long  paddle  crush  any 
apple  that  may  have  remained  whole  against  the  sides  of  the- 
steam-pan.  Then  replace  the  cover  and  steam  for  about  ten 
minutes  more.  The  pulp  is  then  ready  for  immediate  use  or 
storage. 

All  berry  fruit-pulp  will  keep  best  when  poured  boiling  hot 
into  glass  jars  that  have  been  rinsed  out  with  boiling  water. 
Fill  the  jars  to  the  top  and  close  at  once.  Sterilizing  in  tins 
alters  the  color  of  berry  fruit-pulp.  Lower  grade  fruit-pulp, 
of  which  large  quantities  are  made  for  stock,  may  be  stored  in 
tins  holding  up  to  50  Ibs.  as  follows :  The  tins,  which  are  sol- 
dered top  and  bottom,  have  a  two-inch  hole  in  the  lid  and  are 
stood  in  a  vessel  of  boiling  water.  When  the  fruit-pulp  is 
boiling  hot  the  tins  are  taken  out  in  succession  and  filled  up 
to  the  top,  the  lids  being  soldered  on  at  once.  The  tins  are 
then  stood  on  their  heads,  so  that  the  small  amount  of  im- 
prisoned air  is  compelled  to  rise  through  the  boiling  hot  pulp, 
and  is  thus  rendered  innocuous.  This  method  is  perfectly 
reliable,  and  large  quantities  of  pulp  can  thus  be  prepared  for 
storage  in  a  short  time. 

From   France  a  very  fine  perfumed  apple  marmalade  is- 


458  MANUFACTURE    OF    VINEGAR. 

brought  into  commerce.  It  is  prepared  from  equal  parts  of 
Calvilles  and  Pippins,  and  after  boiling  is  sprinkled  with  rose- 
water  or  violet  essence. 

The  term  tutti-frutti  is  applied  to  marmalade  prepared  from 
a  mixture  of  different  kinds  of  fruit.  As  the  name  implies,  it  is 
of  Italian  origin.  The  composition  is  made  according  to  taste 
and  the  fruits  at  disposal. 

English  orange  marmalade  is  made  from  bitter  oranges.  Cut 
the  fruit  into  halves  without  injuring  the  core,  throw  into 
boiling  water,  a  few  at  a  time,  boil  for  several  minutes  and 
then  cool  them  quickly.  The  flesh  can  be  easily  squeezed 
away  from  the  rind.  Heat  the  flesh  to  boiling  with  a  suffi- 
cient quantity  of  water  and  pulp  it  in  a  mill,  quarter  the  rind 
and  cut  it  into  thin  slices,  a  special  machine  being  used  for 
this  purpose.  Blanch  the  slices  until  soft  and  lay  them  aside 
in  a  sieve.  Next  weigh  out  30  parts  of  the  pulp  and  10  of 
the  slices  and  mix  thoroughly.  In  the  meantime  dissolve  54 
parts  of  refined  sugar  and  6  of  syrup  and  heat  till  they  ball. 
Then  add  the  pulp  and  rind  and  boil  the  whole  to  a  finish. 
The  marmalade  should  have  a  golden-yellow  color  and  be 
perfectly  clear.  It  is  filled  hot  into  the  pots  and  fastened 
down  when  cold.  The  orange  pulp  is  sometimes  mixed  with 
half  its  weight  of  apple  pulp. 

Jelly. — This  product  is,  unfortunately,  often  made  expensive 
and  at  the  same  time  spoiled  by  too  large  an  addition  of  sugar. 
Many  housekeepers  do  not  like  to  prepare  jellies  under  the  im- 
pression that  they  require  too  much  sugar  ;  but  this  is  an  error, 
because  in  France,  in  factories  as  well  as  in  households,  they 
use  only  f  pound,  or  at  the  utmost  f  pound,  of  sugar  to  the 
pound  of  fruit,  instead  of  1  pound  or  even  1J  pounds,  as  is 
customary  in  England,  Germany,  and  parts  of  the  United 
States.  Moreover,  the  apple-jelly  which  is  made  in  the  United 
States  and  sent  to  all  parts  of  the  world  is  made  without  any 
addition  of  sugar.  Instead  of  apples,  as  the  raw  material, 
apple-juice  is  used,  which  must  be  perfectly  sweet  and  treated 
immediately  after  it  comes  from  the  press.  A  moderate  tern- 


PRESERVATION    OF    FRUIT.  459 

perature  is  absolutely  necessary  for  success,  for,  if  the  juice 
commences  to  ferment — and  it  does  very  rapidly  in  warm 
weather — the  keeping  quality  of  the  jelly  is  injured,  except  it 
be  mixed  with  a  considerable  quantity  of  sugar.  A  tempera- 
ture of  41°  F.  is  considered  the  most  suitable,  and  if  it  rises  to 
above  66°  F.  the  manufacture  is  at  once  stopped.  The  juice 
runs  directly  from  the  press  into  the  boiler,  under  which  a 
strong  fire  is  kept  because  the  starchy  matters  contained  in 
the  juice  are  only  converted  into  sugar  if  the  boiling  down  is 
quickly  effected.  For  this  reason  shallow  pans  offering  a  large 
surface  to  the  fire  are  used.  When  the  juice  commences  to 
boil  it  is  clarified,  and  the  acid  it  contains  neutralized  by  the 
addition  of  one  teaspoonful  of  elutriated  chalk  to  each  quart  of 
juice.  The  chalk  weighed  off  in  this  proportion  is  mixed  with 
the  juice,  and  appears  in  a  few  minutes  as  a  thick  scum  upon 
the  surface,  from  which  it  is  carefully  removed  with  a  skimmer. 
By  this  operation  the  jelly  is  clarified,  and  all  the  albuminous 
substances  contained  in  it  being  removed  by  the  chalk,  filter- 
ing is  not  required.  The  process  is  similar  to  the  defecation 
of  the  juice  of  sugar-cane  and  beets  by  lime.  The  juice  is  now 
boiled  to  the  consistency  of  30°  or  32°  B.,  which  is  found  on 
cooling  to  be  the  proper  point  for  perfect  jelly.  It  is  then  filled 
direct  from  the  pan  into  tumblers,  which  are  treated  in  the 
same  manner  as  marmalade  jars. 

Successful  jelly  boiling  on  a  large  scale  is  impossible  with- 
out the  use  of  the  saccharometer.  It  is  the  only  reliable  guide 
for  the  addition  of  sugar,  for  if  the  product  is  to  be  protected 
from  spoiling  it  must  show  from  30°  to  32°.  If  this  result  can 
be  reached  without  the  addition  of  sugar,  it  is  so  much  the 
better. 

Pear  and  mulberry  jellies  are  prepared  in  exactly  the  same 
manner  as  above.  Other  fruits  containing  more  acid  require 
an  addition  of  sugar,  especially  currants,  which  next  to  apples 
and  pears  are  most  used  for  jelly,  but  in  no  case  is  the  same 
weight  of  juice  and  sugar  required. 

To  prepare  jelly  from  berries  and  other  small  fruits,  pour  hot 


460  MANUFACTURE    OF    VINEGAR. 

water  over  the  fruit  in  order  to  free  it  from  adhering  dirt  and 
to  facilitate  the  separation  of  the  juice.  When  the  water  is 
cool  take  the  berries  out,  express  the  juice,  and  bring  the  latter 
immediately  into  a  copper  or  brass  kettle  over  a  lively  fire. 
Then  stir  in  pulverized  sugar,  the  quantity  of  which  varies 
according  to  the  variety  of  fruit.  For  raspberries,  strawberries, 
and  blackberries  J  pound  of  sugar  to  the  pound  of  juice  will 
be  sufficient,  and  f  pound  or  at  the  utmost  f  pound  for  cur- 
rants, barberries,  elderberries  and  whortleberries.  The  sugar 
being  added,  stir  in  the  chalk  in  the  proportion  previously 
given,  and  after  allowing  the  juice  to  boil  not  longer  than  15 
minutes,  take  it  from  the  fire  and  strain  it  at  once  into  the 
glasses.  In  this  manner  a  clear,  beautiful  jelly  of  an  agreeable 
taste  will  be  obtained.  If,  on  the  other  hand,  the  juice  is 
boiled  slowly  over  a  weak  fire,  the  result  will  be  a  turbid 
product  which  has  lost  its  fruity  taste. 

Stone-fruit  is  boiled,  and  after  boiling  it  with  a  small  quan- 
tity of  water  until  soft,  the  juice  is  pressed  out  and  f  pound 
of  sugar  added  for  every  pound.  It  should  be  boiled  quickly, 
and  not,  as  some  receipts  have  it,  for  f  hour.  Quinces  are 
peeled  and  then  treated  like  stone-fruit.  Rhubarb  is  cut  into 
small  pieces  and  then  treated  in  the  same  manner.  A  quite 
good  jelly  can  also  be  prepared  from  the  medlar,  provided  it  is 
allowed  to  become  completely  ripe,  and  is  then  slowly  steamed 
with  a  very  small  quanity  of  water.  When  thoroughly  soft 
the  juice  is  pressed  out  and  f  pound  of  sugar  added  to  each 
quart.  The  mass  is  sharply  boiled  for  20  minutes,  when  the 
result  will  be  a  clear  jelly. 

In  France,  as  previously  mentioned,  perfumed  marmalade  is 
prepared  from  equal  parts  of  Calvilles  and  Pippins.  From  the 
same  material,  which  is  considered  best  for  the  purpose,  a  per- 
fumed jelly  is  also  prepared.  The  apples  are  not  peeled,  but 
cut  into  slices,  and  boiled  with  a  small  quantity  of  water  until 
soft  enough  to  be  pressed  in  a  filter-bag.  To  every  pound  of 
juice  }  pound  of  sugar  is  added,  and  five  minutes  before  the 
saccharometer  indicates  30°  B.,  J  or  J  pound  of  violet  bios- 


PRESERVATION    OF    FRUIT.  461 

soms  is  stirred  into  the  juice,  a  few  drops  of  cochineal  being 
generally  added  to  improve  the  color.  The  jelly,  when 
finished,  is  strained  through  a  hair-sieve  into  wide-mouthed 
bottles,  which  are  corked  and  sealed. 

A  jelly  is  made  from  raspberries,  and  sometimes  also  from 
strawberries  and  blackberries,  in  which  the  berries  remain  in- 
tact. The  process  consists  in  dissolving  2  pounds  of  white 
sugar  in  water  and  boiling  until  thickly  fluid.  Two  pounds  of 
berries  are  then  brought  into  the  kettle  and  carefully  mixed 
with  the  sugar  so  as  to  avoid  crushing.  The  kettle  is  then 
taken  from  the  fire  and  allowed  to  stand  covered  for  15 
minutes,  when  it  is  replaced  on  the  fire  and  the  sugar  boiled 
up  once  more.  The  product  is  kept  in  jars  well  corked  and 
sealed. 

A  description  of  the  process  of  manufacturing  apple  jelly 
in  one  of  the  largest  plants  for  that  purpose  may  here  be 
given. 

The  factory  is  located  on  a  creek  which  affords  the  neces- 
sary power.  A  portion  of  the  main  floor,  first  story,  is  occu- 
pied as  a  saw-mill,  the  slabs  furnishing  fuel  for  the  boiler 
furnace  connected  with  the  evaporating  department.  Just 
above  the  mill,  along  the  bank  of  the  pond  and  with  one  end 
projecting  over  the  water,  are  arranged  eight  large  bins  hold- 
ing from  500  to  1000  bushels  each,  .into  which  the  apples  are 
delivered  from  the  teams.  The  floor  in  each  of  these  bins  has 
a  sharp  pitch  or  inclination  towards  the  water,  and  at  the 
lower  end  is  a  gate  through  which  the  fruit  is  discharged, 
when  wanted,  into  a  large  trough  half  submerged  in  the  pond. 

Upon  hoisting  a  gate  in  the  lower  end  of  this  trough  con- 
siderable current  is  caused,  and  the  water  carries  the  fruit  a 
distance  of  from  30  to  100  feet,  and  passes  into  the  basement 
of  the  mill,  where,  tumbling  down  a  four-foot  perpendicular 
fall  into  a  tank,  tight  in  its  lower  half  and  slatted,  so  as  to 
permit  the  escape  of  water  and  impurities,  while  in  the  upper 
half,  the  apples  are  thoroughly  cleansed  from  all  earthy  or 
extraneous  matter.  Such  is  the  friction  caused  by  the  concus- 


462  MANUFACTURE    OF    VINEGAR. 

sion  of  the  fall,  the  rolling  and  rubbing  of  the  apples  together, 
and  the  pouring  of  the  water,  that  decayed  sections  of  the  fruit 
are  ground  off  and  the  rotten  pulp  passes  away  with  otHer  im- 
purities. From  this  tank  the  apples  are  hoisted  upon  an  end- 
less chain  elevator,  with  buckets  in  the  form  of  a  rake-head 
with  iron  teeth,  permitting  drainage  and  escape  of  water,  to 
an  upper  story  of  the  mill,  whence  by  gravity  they  descend  to 
the  grater.  The  press  is  wholly  of  iron  ;  all  its  motion,  even 
to  the  turning  of  the  screws,  being  actuated  by  the  water- 
power. 

The  cheese  is  built  up  with  layers  inclosed  in  strong  cotton 
cloth,  which  displaces  the  straw  used  in  olden  times  and  serves 
also  to  strain  the  juice.  As  it  is  expressed  from  the  press  tank 
the  juice  passes  to  a  storage  tank  and  thence  to  the  defecator. 
This  defecator  is  a  copper  pan  11  feet  long  and  about  3  feet 
wide.  At  each  end  of  this  pan  is  placed  a  copper  tube  3  feet 
inches  in  diameter  and  closed  at  both  ends.  Lying  between 
and  connecting  these  two  are  twelve  tubes  also  of  copper,  1 J 
inch  in  diameter,  penetrating  the  larger  tubes  at  equal  distances 
from  their  upper  and  under  surfaces,  the  smaller  being  paral- 
lel with  each  other  and  1J  inch  apart.  When  placed  in  posi- 
tion the  larger  tubes,  which  act  as  manifolds,  supplying  the 
smaller  with  steam,  rest  upon  the  bottom  of  the  pan,  and  thus 
the  smaller  pipes  have  a  space  of  }  inch  underneath  their 
outer  surfaces. 

The  apple-juice  comes  from  the  storage  tank  in  a  continu- 
ous stream  about  f  inch  in  diameter.  Steam  is  introduced  to 
the  large  or  manifold  tubes,  and  from  them  distributed  through 
the  smaller  ones  at  a  pressure  of  from  25  to  30  Ibs.  per  inch. 
Trap-valves  are  provided  for  the  escape  of  water  formed  by 
condensation  within  the  pipes. 

The  primary  object  of  the  defecator  is  to  remove  all  im- 
purities and  perfectly  clarify  the  liquid  passing  through  it. 

All  portions  of  pomace  and  other  minute  particles  of  foreign 
matter,  when  heated,  expand  and  float  in  the  form  of  scum 
upon  the  surface  of  the  juice.  An  ingeniously  contrived  float- 


PRESERVATION    OF    FRUIT.  463 

ing  rake  drags  off  this  scum  and  delivers  it  over  the  side  of  the 
pan.  To  facilitate  this  removal,  one  side  of  the  pan,  com- 
mencing at  a  point  just  below  the  surface  of  the  juice,  is  curved 
gently  outward  and  upward,  terminating  in  a  slightly  inclined 
plane,  over  the  edge  of  which  the  scum  is  pushed  by  the  rake 
into  a  trough  and  carried  away. 

A  secondary  purpose  served  by  the  defecator  is  that  of 
reducing  the  juice  by  evaporation  to  a  partial  syrup  of  the 
specific  gravity  of  about  20°  B.  When  of  this  consistency  the 
liquid  is  drawn  from  the  bottom  and  the  less  agitated  portion 
of  the  defecator  by  a  syphon  and  thence  carried  to  the  evap- 
orator, which  is  located  upon  the  same  framework  and  just 
below  the  defecator. 

The  evaporator  consists  of  a  separate  system  of  six  copper 
tubes,  each  12  feet  long  and  3  inches  in  diameter.  These  are 
jacketed,  or  inclosed  in  an  iron  pipe  of  4  inches  internal  diam- 
eter, fitted  with  steam-tight  collars  so  as  to  leave  half  an  inch 
space  surrounding  the  copper  tubes.  The  latter  are  open  at 
both  ends,  permitting  the  admission  and  egress  of  the  syrup 
and  the  escape  of  the  steam  caused  by  evaporation  therefrom, 
and  are  arranged  upon  the  frame  so  as  to  have  a  very  slight 
inclination  downward  in  the  direction  of  the  current,  and 
each  nearly  underneath  its  predecessor  in  regular  succession. 
Each  is  connected  by  an  iron  supply-pipe,  having  a  steam- 
gauge  or  indicator  attached,  with  a  large  manifold,  and  that 
by  other  pipes  with  a  steam  boiler  of  30  horse-power  capacity. 

Steam  being  let  on  at  from  25  to  30  Ibs.  pressure,  the  stream 
of  syrup  is  received  from  the  defecator  through  a  strainer, 
which  removes  any  impurity  possibly  remaining,  into  the 
upper  evaporator  tube;  passing  in  a  gentle  flow  through  that, 
it  is  delivered  into  a  funnel  connected  with  the  next  tube  be- 
low, and  so  back  and  forth  through  the  whole  system.  The 
syrup  enters  the  evaporator  at  a  consistency  of  from  20°  to 
23°  B.,  and  emerges  from  the  last  tube,  some  three  minutes 
later,  at  a  consistency  of  from  30°  to  32°  B.,  which  is  found 
on  cooling  to  be  the  proper  point  for  perfect  jelly.  This 


464  MANUFACTURE    OF    VINEGAR. 

point  is  found  to  vary  one  or  two  degrees,  according  to  the 
fermentation  consequent  upon  bruises  in  handling  the  fruit, 
decay  of  the  same,  or  any  little  delay  in  expressing  the  juice 
from  the  cheese.  The  least  fermentation  occasions  the  neces- 
sity for  a  lower  reduction.  To  guard  against  this,  no  cheese 
is  allowed  to  stand  over  night,  no  pomace  left  in  the  grater 
-or  vat,  no  juice  in  the  tank ;  and  further  to  provide  against 
fermentation,  a  large  water  tank  is  located  upon  the  roof  and 
filled  by  a  force-pump,  and  by  means  of  hose  connected 
with  this,  each  grater,  press,  vat,  tank,  pipe,  trough,  or 
other  article  of  machinery  used  can  be  thoroughly  washed 
-and  cleansed.  Hot  water  instead  of  juice  is  sometimes  sent 
through  the  defecator,  evaporator,  etc.,  until  all  are  thoroughly 
scalded  and  purified. 

If  the  saccharometer  shows  too  great  or  two  little  reduction, 
:the  matter  is  easily  regulated  by  varying  the  steam  pressure 
in  the  evaporator  by  means  of  a  valve  in  the  supply  pipe. 

If  boiled  cider  instead  of  jelly  is  wanted  for  making  pies, 
sauces,  etc.,  it  is  drawn  off  from  one  of  the  upper  evaporator 
tubes,  according  to  the  consistency  desired  ;  or  it  can  be  pro- 
cured at  the  end  of  the  process  by  simply  reducing  the  steam 
pressure. 

As  the  jelly  emerges  from  the  evaporator  it  is  transferred  to 
.a  tub  holding  some  50  gallons,  and  by  mixing  a  little  therein 
•any  slight  variations  in  reduction  or  in  the  sweetness  or  sour- 
ness of  the  fruit  used  are  equalized.  From  this  it  is  drawn 
through  faucets,  while  hot,  into  the  various  packages  in  which 
it  is  shipped  to  market. 

A  favorite  form  of  package  for  family  use  is  a  nicely  turned 
little  wooden  bucket  with  cover  and  bail,  of  two  sizes,  holding 
5  and  10  pounds  respectively.  The  smaller  packages  are 
shipped  in  cases  for  convenience  in  handling. 

Each  bushel  of  fruit  will  produce  from  4  to  5  pounds  of 
jelly,  fruit  ripening  late  in  the  season  being  more  productive 
than  other  varieties.  Crab-apples  produce  the  finest  jelly,  sour 
•crabbed  natural  fruit  makes  the  best-looking  article,  and  a 


EVAPORATION    OF    FRUIT.  465 

mixture  of  all  varieties  gives  most  satisfactory  results  as  to 
flavor  and  general  quality. 

Saving  of  the  Apple  Seeds. — As  the  pomace  is  shoveled  from 
the  finished  cheese  it  is  again  ground  under  a  toothed  cylinder, 
and  thence  drops  into  large  troughs  through  a  succession  of 
which  a  considerable  stream  of  water  is  flowing.  Here  it  is 
occasionally  agitated  by  raking  from  the  lower  to  the  upper 
end  of  the  trough,  as  the  current  carries  it  downward,  and  the 
apple  seeds  becoming  disengaged  drop  to  the  bottom  into  still 
water  while  the  pulp  floats  away  upon  the  stream.  A  succes- 
sion of  troughs  serves  to  remove  nearly  all  the  seeds. 


CHAPTER  XXXII. 

EVAPORATION    OF    FRUIT. 

EVAPORATION  is  one  of  the  most  important  methods  em 
ployed  for  preserving  fruit  for  any  length  of  time.  The  rea- 
son for  this  can  be  readily  given  :  The  process  does  not  require 
great  technical  skill ;  it  excels  in  cheapness  because  neither 
vessels,  sugar  nor  other  auxiliaries  are  required  ;  the  product 
possesses  excellent  keeping  qualities,  retains  its  natural  flavor, 
and  by  many  is  considered  healthier  and  more  agreeable  than 
fruit  preserved  by  any  other  method.  While  much  fruit  is 
still  dried  in  the  sun,  and  large  quantities  of  it  are  marketed, 
the  superiority  of  evaporated  fruit  has  caused  a  large  demand 
for  it,  and  aside  from  the  consumption  in  this  country,  large 
amounts  are  shipped  abroad. 

The  Alden  patent  for  evaporating  fruit  was  granted  about 
40  years  ago.  Like  all  other  new  inventions,  some  years 
were  required  before  its  merits  became  thoroughly  under- 
stood, though  at  the  Paris  Exposition  of  1878  the  first  prize 
was  unanimously  awarded  to  the  fruit  dried  by  that  process. 
Since  then  it  has  spread  from  California,  where  it  was  first 
30 


4G6  MANUFACTURE  OF  VINEGAR. 

introduced,  throughout  the  entire  country,  and  though  many 
types  of  evaporators  are  now  in  use,  they  are  all  based  upon 
the  same  principle.  At  first  only  kernel  and  stone-fruits  were 
evaporated,  but  at  present  the  list  includes  almost  every 
known  fruit  and  vegetable. 

Before  entering  upon  a  description  of  the  apparatus  and  its 
use,  an  explanation  of  the  principle  upon  which  it  is  based 
and  the  theory  of  evaporating  fruit  will  be  given. 

The  object  to  be  attained  is  not  only  to  make  the  fruit  keep, 
but  also  to  retain  the  properties  for  which  it  is  valued.  This 
can  only  be  reached  by  withdrawing  the  content  of  water,  and 
at  the  same  time  converting  a  portion  of  the  starch  into  sugar 
in  as  short  a  time  as  possible  without  boiling  the  fruit.  The 
latter  would  injure  the  taste  of  the  fruit,  and  slow  drying  gives 
a  flavor  calling  to  mind  decay.  The  more  quickly  the  watery 
portions  are  removed  from  thoroughly  ripe  fruit,  the  richer 
and  more  durable  its  taste  will  be ;  and  the  more  completely 
the  oxygen  of  the  air  is  excluded  during  this  process,  the  more 
perfectly  will  it  retain  its  color.  Rapidity  of  the  drying  pro- 
cess sometimes  increases  the  content  of  sugar  by  25  per  cent., 
and  this  increase  is  in  an  exact  proportion  to  the  quicker  or 
slower  evaporation  of  the  content  of  water,  always  provided, 
however,  the  fruit  does  not  suffer  injury  from  the  heat. 

Any  one  who  has  boiled  down  the  juice  of  the  maple, 
sorghum,  sugar-cane,  or  sugar  beet  knows  that  with  slow 
evaporation  sugar  is  not  formed,  the  content  of  sugar  being 
then  converted  into  acid.  Now,  the  change  of  substance  must 
be  constantly  kept  in  view  :  Starch  is  converted  into  sugar  (in 
this  case  very  largely  already  in  the  plant),  sugar  into  al- 
cohol, and  alcohol  into  acetic  acid.  This  experience  must  also 
hold  good  in  drying  fruit.  The  chemical  process  by  which 
the  content  of  starch  of  the  fruit,  when  brought  into  a  high 
temperature,  is  converted  into  sugar,  is  similar  to  that  during 
the  ripening  process  on  the  tree,  only  it  takes  place  more 
rapidly. 

A  few  days  of  warm  sunshine  produce  sufficient  sugar  in 


EVAPORATION    OF    FRUIT.       *  467 

gooseberries  and  grapes  to  change  the  sour  unpalatable  fruits 
to  a  refreshing  article  of  food.  A  few  hours  in  an  evaporating 
apparatus,  in  which  the  proper  degree  of  heat  is  maintained, 
can  produce  a  still  greater  change,  provided  the  fruit  be  not 
placed  in  it  before  it  has  reached  perfection  in  a  natural  man- 
ner. It  must  be  remembered  that  212°  F.  is  the  boiling  point, 
and  that  subsequent  treatment,  no  matter  how  careful,  cannot 
restore  the  taste  lost  in  such  a  temperature.  Of  no  less  im- 
portance is  another  point :  The  surface  of  the  fruit  to  be  dried 
must  be  kept  moist  and  soft,  so  that  the  internal  moisture  may 
find  a  way  by  which  it  can  readily  and  quickly  escape,  and  a 
strong  hot  current  of  air  must  uninterruptedly  pass  over  the 
fruit  to  carry  off  the  escaping  moisture.  Hence,  cold  air  must 
under  no  circumstances  have  access  to  drying  fruit,  and  above 
the  latter  an  aperture  must  be  provided  for  the  escape  of  the 
air  saturated  with  moisture. 

The  apprehension  that  fruit  cannot  be  dried  in  a  hot  moist 
apparatus  is  refuted  by  the  well-known  scientific  fact,  that  air 
of  the  temperature  of  the  freezing  point  absorbs  I-J-Q  part  of  its 
weight  of  moisture,  and  that  its  capacity  for  absorption  doubles 
with  every  15°  C..  (27°  F.)  of  higher  temperature.  Thus,  if 
the  temperature  is  59°  F.  it  absorbs  ^V  parts  of  its  weight  of 
water,  81°  F.  ^  part,  113°  F.  ^  part,  140°  F.  ^  part,  167°  F. 
i  part,  194°  F.  i  part,  and  221°  F.  its  own  weight  which  is 
nearly  equal  to  one  pound  of  water  to  every  \  cubic  foot  of 
air. 

The  fruit  would  evidently  never  become  dry  if  the  air  loaded 
with  such  moisture  remained  stationary,  but  set  it  in  motion 
with  a  velocity  of  880  feet  per  minute,  which  is  equal  to  20 
miles  per  hour,  and  the  cause  of  the  rapid  drying,  or,  in  other 
words,  of  the  withdrawal  of  water,  becomes  apparent.  Now  if 
we  figure  to  ourselves  an  apparatus  of  225  cubic  feet  content, 
the  air  heated  in  it  to  212°  F.  contains,  according  to  the  above 
statement,  60  pounds  of  water,  50  pounds  of  which  have  been 
withdrawn  from  the  fruit,  while  the  remaining  10  pounds  were 
contained  in  the  air  prior  to  its  entrance  into  the  apparatus, 


468  MANUFACTURE  OF  VINEGAR. 

because  its  temperature  is  supposed  to  be  62.5°  F.  With 
sufficient  circulation  to  empty  the  apparatus  every  20  minutes 
150  pounds  of  water  will  each  hour  be  carried  away  from  a 
quantity  of  fruit  supposed  to  amount  to  800  pounds.  Hence, 
in  5  hours,  the  time  generally  required  for  apples,  750  pounds 
of  moisture  could  be  removed  if  present. 

Moreover,  reference  to  a  drying  apparatus  is  not  required  to 
prove  that  heat  alone  does  not  suffice  for  drying.  Is  it  not 
the  wind  which  dries  up  the  puddles  after  a  rain  more  quickly 
than  the  hottest  rays  of  the  sun?  The  sun  alone  would  effect 
nothing  else  but  envelop  the  moist  earth  in  a  dense  mantle  of 
vapor  destructive  to  both  men  and  animals.  Thus  in  the  dry- 
ing apparatus  also  it  is  rather  the  current  of  air  which  dries 
than  the  heat,  but,  of  course,  both  must  work  in  conjunction. 
The  rapidity  of  the  process  prevents  decay,  and  causes  the 
color  and  aroma  of  the  fresh  fruit  to  be  retained.  The  greater 
advantage  of  this  rapidity  consists,  however,  in  the  conversion 
of  a  considerable  quantity  of  starch  into  sugar,  which  in  sweet 
fruits,  such  as  peaches,  is  sometimes  formed  in  such  abund- 
ance as  to  appear  in  small  congealed  drops  upon  the  surface. 

From  the  preceding  it  will  also  be  readily  understood  why 
drying  in  the  sun  or  in  the  oven  must  yield  unsatisfactory  re- 
sults. Even  with  favorable  weather  the  process  lasts  about  14 
days.  During  this  long  time  a  fermentation  sets  in  which  par- 
tially destroys  the  content  of  sugar,  and  essentially  changes  the 
color  and  taste  in  an  unfavorable  direction.  Such  fruit  when 
boiled  tastes  as  if  it  had  been  preserved  after  the  appearance 
of  decay.  Besides,  during  this  process,  the  fruit  is  frequently 
selected  as  a  breeding  place  by  insects,  in  consequence  of  which 
it  soon  spoils,  and  when  shipped  to  a  distance  resembles  on 
arrival  at  its  place  of  destination  a  heap  of  maggots.  Such 
cases  are  not  rare,  especially  if  the  dried  fruit  is  shipped  to 
tropical  countries. 

Drying  in  the  oven  has  the  disadvantage  that  the  dry  heat 
immediately  closes  the  pores  of  the  fruit,  thereby  rendering  the 
escape  of  the  internal  moisture  very  difficult.  If  the  heat  is 


EVAPORATION    OF    FRUIT.  469 

not  very  strong  the  fruit  remains  moist  in  the  interior,  which 
causes  it  to  spoil,  and  with  a  strong  heat  the  surface  carbon- 
izes more  or  less.  A  portion  of  the  sweetness  is  lost  by  being 
converted  into  caramel,  the  appearance  of  the  fruit  suffers  by 
the  tough  shriveling  of  the  surface,  and  the  taste  is  injured 
by  carbonization. 

All  these  disadvantages  are  avoided  by  the  modern  evapo- 
rating process,  which  may  be  called  a  preservation  of  the  fruit 
in  its  own  juice  with  the  assistance  of  steam. 

A  chemical  analysis  of  a  parcel  of  Baldwin  apples  shows 
best  the  changes  effected  in  the  composition  of  fruit  by  dry- 
ing  in  the  oven  and  by  evaporation,  and  how  the  results  with 
these  two  methods  compare  with  each  other.  The  first  col- 
umn gives  the  composition  of  500  parts  of  fresh  Baldwin 
apples.  The  second  column  gives  the  composition  of  the  same 
parcel  of  apples  after  being  reduced  to  100  parts  (loss  of  400 
parts  of  water)  by  drying  in  the  oven,  and  a  third  column  the 
result  of  100  parts  of  the  same  parcel  reduced  by  evaporation. 

Dried  in  Evapo- 

Fresh.  the  oven.  rated. 

Water  (free  and  fixed).   .   ...   .    411.15  12.42  16.62 

Cellulose 9.60  10.54  10.22 

Starch 32.95  30.95  29.75 

Protein 0.75  0.80  0.76 

Pectine *...'.    .    .    .      12.35  11.35  10.88 

Gum ."'.  .,    .        6.75  7.22  4.33 

Fruit  acids '.   .   ..    .        6.70  4.88  3.43 

Mineral  constituents  .    .    .'  .   .    .    .        0.85  0.87  0.78 

Chlorophyl >  i  ;  0.15  0.12  0.15 

Dextrin ...,.  2.10 

Grape  sugar •      18.75  18.75  23.08 

Volatile  oils,  traces — 


500.00    100.00    100.00 

Attention  must  especially  be  drawn  to  the  fact  that  dextrin, 
the  formation  of  which  is  due  to  dry  heat,  is  only  found  in  the 
second  column,  and  must  be  considered  as  an  essential  dis- 
advantage of  drying  in  the  oven.  The  absence  of  this  sub- 
stance in  evaporated  fruit,  as  well  as  the  presence  of  a  larger 


470 


MANUFACTURE    OF    VINEGAR. 


FlG>  "' 


quantity  of  water  (chemically  fixed),  is  to  be  ascribed  to  the 
influence  of  moisture  during  evaporation. 

As  previously  mentioned,  many  types  of  evaporators  are 
now  in  use,  some  of  them  being  small  box-like  structures  of 
such  a  size  that  they  can  be  placed  on  top  of  an  ordinary 
cook-stove,  while  others*  have  a  sufficient  capacity  for  hand- 
ling fruit  on  a  very  large  scale. 

Fig.  99  shows  an  improved  Aid  en  evaporator  which,  like 
the  Williams  evaporator  to  be  described  later  on,  belongs  to 
the  type  known  as  tower  evaporators.  A  is  the  air-furnace 

which  is  formed  by  the  fire-box  D, 
the  ash-box  Dlt  and  the  doubled  hori- 
zontal  pipes  G,  of  which,  according  to 
the  size  of  the  apparatus,  there  are 
from  3  to  6,  each  4  inches  in  diameter, 
and  running  parallel  to  each  other. 
The  products  of  combustion  pass 
through  them  in  the  direction  of  the 
arrows,  and  escape  through  the  smoke- 
pipe  0  at  the  back  of  the  apparatus. 
The  fire-box  is  surrounded  by  an  air- 
space provided  at  M  with  apertures. 
Similar  apertures  to  permit  the  en- 
trance of  cold  air  are  provided  on  the 
side  near  the  foot  of  the  brick  casing. 
The  cold  air  comes  first  in  contact 
with  the  lower,  only  moderately  heated 
pipe,  then  rises  to  the  second,  and 
finally  to  the  third  and  hottest  series 
of  pipes.  It  is  thus  gradually  heated, 
and  the  pipes  lying  close  together,  each 
atom  of  air  comes  in  contact  with  them, 

which  is  considered  a  better  mode  of  heating  than  by  radia- 
tion, formerly  used.  The  pipes  are  of  cast-iron,  and  an  escape 
of  smoke  into  the  drying-tower  is  impossible.  By  always 
keeping  the  pipes  clean,  which  can  be  conveniently  done,  the 


EVAPORATION    OF    FRUIT.  471 

heat  passes  rapidly  through  their  walls,  and  ascends  im- 
mediately into  the  drying-tower  without  the  possibility  of 
super-heating. 

The  draught-pipe  d  connects  the  exit  of  the  drying-tower 
with  the  fire-box  of  the  furnace.  The  importance  of  this  ven- 
tilation is  sufficiently  shown  by  the  statement  that  for  com- 
bustion 25,000  cubic  feet  of  air  per  hour  are  required,  which 
are  introduced  from  the  neighborhood  of  the  opening  of  the 
tower  through  the  pipe  d  into  the  fire-box.  The  removal  of 
such  a  considerable  quantity  of  air  produces  a  vacuum  in  the 
upper  portion  of  the  tower,  and  consequently  a  very  quick  cur- 
rent of  air  over  the  trays  of  fruit  in  the  tower— an  absolute 
requirement  for  attaining  great  perfection  in  the  art  of  drying 
fruit  by  evaporation.  Besides,  a  saving  of  fuel  is  effected  by 
the  introduction  of  air,  already  heated,  into  the  fire-box.  The 
smoke-pipe  0  is  surrounded  by  a  wooden  jacket,  leaving  a  small 
intermediate  space  in  which  the  heat  radiating  from  the  pipe 
collects,  and  is  forced  to  enter  the  tower  below  the  discharge- 
door.  This  also  accelerates  the  current  of  air  in  the  tower  and 
prevents  the  condensation  of  the  moisture,  so  that  the  fruit 
completely  dries  off  in  a  short  time.  The  branch-pipe/con- 
nects the  opening  of  the  tower  with  the  smoke-pipe,  which  by 
its  power  of  absorption  also  increases  the  current  of  air.  The 
draught-pipe  c  is  provided,  as  will  be  readily  seen,  for  the 
purpose  of  uniformly  distributing  the  heat  in  the  tower. 

The  bulb  of  the  thermometer,  with  which  the  apparatus  is 
provided,  is  placed  in  the  interior  of  the  tower  and  the  scale 
on  the  outside,  so  that  the  temperature  can  be  read  off  without 
opening  a  door,  whereby  cold  air  would  enter,  which  must  be 
avoided.  The  air-furnace  is  constructed  of  brick,  and  the 
tower,  as  well  as  the  draught-pipes  d  and  c  and  the  jacket  of 
the  smoke-pipe  0,  of  double  boards. 

The  hurdles  or  trays  for  the  fruit  consist  of  wooden  frames 
with  galvanized  iron-wire  bottoms.  They  hold  from  20  to  60 
Ibs.  of  fruit  each,  and  when  charged  are  pushed  through  the 
door  over  the  air-furnace  into  the  tower,  where  they  rest  upon 


472  MANUFACTURE    OF    VINEGAR. 

pins  of  an  endless  chain  set  in  motion  by  a  wheel,  as  seen  in 
the  illustration.  The  trays  sit  close  to  the  walls  on  two  sides 
of  the  tower,  while  in  the  other  direction  there  is  an  inter- 
space of  two  inches.  The  first  tray  is  pushed  tight  against 
the  back  wall,  the  mentioned,  interspace  thus  remaining  in 
front  of  the  door. 

After  six  to  ten  minutes,  according  to  the  variety  of  fruit, 
the  tray  is  raised  five  inches  by  means  of  the  endless  chain  ; 
the  second  tray  is  then  placed  in  position,  but  so  that  the 
above-mentioned  intermediate  space  is  at  the  back  wall.  At 
regular  intervals  the  trays,  when  placed  in  position,  are  raised 
by  the  endless  chain  and  the  fresh  trays  pushed  in,  so  that 
they  touch  alternately  the  front  and  back  wall,  the  current  of 
air  being  thus  forced  to  ascend  in  a  zigzag.  When  the  tower 
is  filled  with  trays  it  contains — taking  apples  as  an  example 
—from  1200  to  3000  Ibs.  of  fruit.  Every  50  Ibs.  of  each  yield 
from  40  to  45  Ibs.  of  water,  which  ascends  as  vapor,  which  by 
surrounding  the  fruit  with  a  moist  mantle  prevents  its  burn- 
ing and  keeps  the  pores  open.  When  the  tray  first  placed  in 
position  arrives  at  the  discharge-door  it  has  been  in  the  tower 
for  about  five  hours,  and  its  contents  have  been  converted 
into  evaporated  fruit  which  will  keep  for  many  years.  Thus 
fruit  can  be  gathered,  evaporated  and  sold  all  in  one  day. 

By  considering  the  construction  of  the  tower  it  will  be  seen 
that  the  fruit  during  its  ascent  remains  in  a  uniform  moisture 
and  heat,  so  that  up  to  the  moment  it  is  taken  from  the  appa- 
ratus, its  content  of  water  can  escape  through  the  opened 
pores  and,  on  the  other  hand,  the  heat  can  act  to  its  very 
center.  A  uniform,  perfect  product  can  be  obtained  only  by 
these  means.  When  the  fruit  arrives  at  the  discharge-door  it 
is  cool  and  as  soft  as  fresh  fruit. 

Fig.  100  shows  the  Williams  evaporator.  It  is  heated  by 
steam  radiators  located  at  the  base  of  the  vertical  tower  and 
has  vertical  radiating  pipes  up  the  center  of  the  vertical  tower, 
around  which  the  trays  of  fruit  revolve,  with  deflectors  at  in- 
tervals of  two  feet  projecting  from  each  side  of  said  pipes  to 


EVAPORATION    OF    FRUIT. 


FIG.  100. 


474  MANUFACTURE    OF    VINEGAR. 

direct  the  heat  under  the  trays  of  fruit  as  they  revolve  around 
the  pipes.  (The  trays  and  hanger  are  left  out  in  the  illustra- 
tion to  show  the  interior  arrangement  of  the  pipes.)  These 
pipes  or  radiators  extending  up  the  tower  from  bottom  to  top 
produce  a  uniform  heat  the  entire  length  of  the  tower,  and 
increase  the  draught  by  increasing  the  heat  at  the  top,  which 
produces  a  more  rapid  circulation  than  when  the  heat  is  all 
at  the  bottom,  as  with  the  hot-air  furnace  ;  and  the  capacity 
of  the  apparatus  is  also  increased  in  proportion  to  the  increase 
of  the  heat  and  the  draught  through  the  tower.  The  trays 
of  fruit  in  passing  up  the  tower  are  exposed  from  one  side  to 
the  pipes,  and  on  descending  are  exposed  from  the  other, 
which  causes  the  fruit  to  dry  uniformly.  The  tower  being 
vertical  the  heat  is  utilized  until  it  reaches  the  top.  In  this 
apparatus  a  very  strong  heat  can  be  had  throughout  the  en- 
tire length  of  the  tower,  without  incurring  any  risk  of  fire 
from  siftings  from  the  trays,  when  drying  cores  and  skins, 
falling  on  the  hot-air  furnace,  which  is  always  placed  directly 
under  the  tower.  Several  sizes  of  this  evaporator  are  manu- 
factured. 

The  manner  of  operating  the  Alden  apparatus  is  as  follows  : 
The  maintenance  of  a  uniform  temperature  in  the  tower 
being  essential,  the  thermometer  should  indicate  194°  to  212° 
F.  Berries  and  stone  fruit  are  to  be  kept  somewhat  cooler. 
The  introduction  of  too  much  cold  air  into  the  air  furnace 
must  be  avoided.  As  a  rule  an  aperture  two  feet  square 
suffices. 

The  upward  motion  of  the  trays  must  be  effected  at  regular 
intervals.  How  long  these  intervals  are  to  be,  cannot  be 
•definitely  stated,  it  depending  on  the  content  of  water  in  the 
fruit  and  on  the  temperature  of  the  tower.  The  following 
table  may,  however,  serve  as  a  guide : 


EVAPORATION    OF    FRUIT.  475 

Apples interval  6  to  10  minutes. 


"     12  ; 

20 

K    15  <• 

20 

(C 

«      8  ' 

15 

tt 

"      10  ' 

20 

t| 

'4         1Q    ' 

90 

<4 

"       fi  ' 

0 

« 

"       5  c 

7 

it 

t  < 

<i       on  u 

9JS 

It  is  supposed  that  the  temperature  directly  above  the  air- 
furnace  is  212°  F.,  and  it  is  best  to  keep  it  at  that  degree  ex- 
cept for  berries  and  stoned  fruit,  for  which  it  may  be  from  41° 
to  50°  less.  As  previously  stated,  it  is  an  essential  condition 
that  the  fruit  should  not  boil.  This  will,  however,  not  be  the 
case  at  the  temperature  mentioned,  because  the  fruit  remains 
too  short  a  time  in  it,  and  in  rising  upwards  meets  a  some- 
what more  moderate  heat.  As  a  rule,  it  may  be  said  that  as 
high  a  temperature  as  possible  is  most  advantageous,  provided 
boiling  be  avoided. 

The  evaporated  fruit,  when  taken  from  the  tower,  is  spread 
out  in  an  airy  room,  where  it  remains  for  a  few  hours  to  dry 
off  previous  to  packing.  Care  must  be  had  that  during  this 
time  it  does  not  come  in  contact  with  insects,  and  to  prevent 
this  the  windows  and  air-holes  should  be  provided  with  screens, 
or  the  fruit  covered  with  mosquito  netting.  The  fruit  when 
ready  for  packing  is  put  in  boxes  as  follows :  Line  the  box 
with  colored  paper  with  the  ends  projecting  above  the  edge. 
Then  fill  the  box  with  fruit.  Kernel  fruit  is  piled  up  about 
one  inch  above  the  edge  of  the  box,  while  stone  fruit  is  not 
piled  so  high,  it  being  subsequently  not  subjected  to  pressure. 
To  press  down  the  contents  even  with  the  edge  of  the  box  a 
weight,  or,  still  better,  a  press  is  used.  After  pressing,  fold 
the  ends  of  the  paper  over  the  fruit,  nail  down  the  lid,  and  put 
on  the  label. 

Sliced  evaporated  apples  are  packed  as  follows :  Line  the 


476  MANUFACTURE    OF    VINEGAR. 

box  with  white  paper,  one  piece  on  the  bottom  and  four  pie  - 
on  the  sides  long  enough  to  fold  over.  Then  nail  down  the 
lid.  take  off  the  bottom,  and  commence  packing  by  placing 
one  layer  of  slices  in  the  manner  of  roof-tiles.  Sufficient  fruit 
to  make  up  the  required  weight  is  then  piled  in,  and  after 
pressing  down  the  box  is  nailed  up  and  labeled.  A  general 
rule  as  regards  weight  has  not  been  introduced,  though  in 
California  all  varieties  of  evaporated  fruit  are  packed  in  boxes 
holding  50  pounds  net. 

In  recent  years  tower  evaporators  have  been  largely  super- 
seded, especially  for  evaporating  apples,  by  the  kiln  evaporator. 
This  type  is  described  by  H.  T.  Gould*  as  follows :  "  While  the 
principles  of  construction  of  the  different  evaporators  of  this 
type  are  similar  in  all  cases,  the  details  of  the  arrangement  of 
the  appliances  are  endlessly  varied. 

"  In  constructing  kilns  the  same  general  principles  are  fol- 
lowed, whether  the  evaporator  is  a  small  one  with  only  a  sin- 
gle kiln  or  an  extensive  establishment  having  several  of  them. 
The  most  satisfactory  size  of  a  kiln,  all  things  considered,  is 
about  20  feet  square.  This  is  a  convenient  size  to  fill,  so  far 
as  the  preparation  of  the  fruit  is  concerned ;  the  heat  can  be 
well  regulated,  made  sufficiently  intense  for  the  purpose  de- 
sired, and  evenly  distributed,  so  that  the  fruit  will  dry  uni- 
formly, and  for  various  minor  reasons  a  kiln  of  this  size 
is  a  desirable  'unit '  in  the  construction  of  evaporators  of  this 
type. 

"A  kiln  consists  essentially  of  a  floor  made  of  slats  and 
placed  over  a  furnace  room  or  over  a  system  of  steam  pipes. 
The  floor  is  usually  built  from  10  to  12  feet  above  the  floor  of 
the  furnace  room.  Provision  should  be  made  for  regulating 
the  heat  by  means  of  small  openings  in  the  base  of  the  walls 
communicating  with  the  outside  which  can  be  opened  or 
closed  as  desired.  The  inflow  of  cold  air  can  thus  be  regu- 
lated. Such  control  is  specially  desirable  in  windy  weather. 

*U.  S.  Department  of  Agriculture.   Farmer's  Bulletin  291.  Washington,  1907. 


EVAPORATION    OF    FRUIT.  477 

While  many  evaporators  are  constructed  without  special  pro- 
vision of  this  kind,  it  is  an  important  point  to  have  such 
openings,  particularly  if  the  walls  are  brick  or  otherwise  made 
very  tight,  so  that  there  is  but  little  circulation  of  air. 

"  If  the  evaporator  is  a  frame  building,  the  walls  of  the 
furnace  room  may  be  well  plastered  or  covered  with  asbestos 
paper  to  lessen  the  danger  from  fire,  which  may  otherwise  be 
great,  because  of  the  intense  heat  generated  within  them. 

"If  the  walls,  at  least  the  portion  below  the  kiln  floor,  are 
double,  with  an  air-space  between  the  two  sides,  the  insula- 
tion will  be  more  perfect  than  if  they  are  solid  or  of  only  a 
single  thickness,  thus  best  conserving  the  heat  and  increasing 
the  efficiency  of  the  plant  The  height  of  the  walls  of  the 
kiln  above  the  drying  floor  should  be  sufficient  to  permit  an 
attendant  to  work  on  the  floor  conveniently  and  with  comfort. 

"  Some  means  for  the  escape  of  the  air  laden  with  moisture 
from  the  fruit  is  necessary.  This  may  be  provided  for  by 
means  of  an  opening  in  the  roof,  or  a  cupola-like  ventilator 
may  be  built,  the  sides  of  which  should  consist  of  slats  placed 
so  that  they  overlap  one  another,  as  in  an  ordinary  window- 
blind.  Another  form  of  ventilator  is  in  the  form  of  a  tower 
about  3  feet  square  and  extending  8  or  10  feet  above  the 
roof,  which  is  sufficiently  bigh  to  cause  more  or  less  draft,  and 
hence  augments  the  circulation  of  hot  air  through  the  fruit, 

••  The  kiln  floor  is  constructed  of  strips  especially  designed 
for  the  purpose.  Such  floors  are  generally  made  of  poplar  or 
basswood  strips,  seven-eighths  of  an  inch  thick,  one  inch  wide 
on  the  top  surface  and  one-half  inch  wide  on  the  under  side. 
In  laying  the  floor  these  strips  are  placed  one-eighth  to  one- 
fourth  inch  apart  on  the  upper  surface.  This  makes  the 
space  between  them  wider  on  the  under  side  than  on  the 
upper,  thus  allowing  the  small  particles  of  fruit  which  work 
down  between  them  to  drop  through  without  clogging  the 
intervening  spaces, 

"Satisfactory  results  are  so  dependent  upon  the  heating 
apparatus  that  this  becomes  one  of  the  most  important  features 


478  MANUFACTURE    OF    VINEGAR. 

of  an  evaporator.  In  the  larger  kiln  evaporators,  ordinary 
cast-iron  stoves  were  formerly  used  considerably,  two  or  more 
of  them  being  frequently  required  to  heat  a  single  kiln,  but 
these  have  largely  gone  out  of  use.  -In  their  stead  large  fur- 
naces are  now  most  commonly  used.  These  are  specially  de- 
signed for  the  purpose  and  are  provided  with  relatively  large 
fire-pots,  correspondingly  large  ash-pits,  and  large  radiating 
surfaces.  As  it  is  necessary  to  burn  a  relatively  large  quantity 
of  fuel  in  a  given  time,  the  size  of  the  grate  is  made  with  this 
end  in  view.  For  a  kiln  floor  20  feet  square,  or  400  square 
feet  of  surface,  the  grate  surface  is  usually  about  3  feet  in 
diameter,  containing  from  5  to  7  square  feet. 

"  As  to  the  most  satisfactory  length  of  pipe  connecting  the 
furnace  and  chimney,  opinions  differ.  Perhaps  the  most 
common  method  of  piping  is  as  follows :  The  furnace,  with 
two  flanges  for  attaching  the  pipe,  is  placed  in  the  center ;  the 
pipe  from  each  flange  is  then  extended  to  the  side  of  the  room 
opposite  the  chimney,  and  from  this  point  the  two  sections, 
extending  in  opposite  directions,  follow  the  wall,  at  a  distance 
of  2  or  3  feet  from  it,  to  the  chimney.  In  a  kiln  20  feet 
square,  some  65  or  70  feet  are  thus  required.  Ten-inch  pipe 
is  a  common  size  to  use  for  this  purpose.  It  is  placed  about 
3  feet  below  the  kiln  floor. 

"  Some  operators  think  that  a  better  distribution  of  heat  is 
obtained  if  the  pipes  extend  back  and  forth,  2  or  3  feet  apart, 
under  the  entire  floor  of  the  kiln,  thus  requiring  200  feet  or 
more  instead  of  the  shorter  length  above  suggested.  The 
greater  length,  however,  is  less  frequently  used  than  the 
smaller. 

"  In  some  cases  the  heat  is  so  intense  directly  over  the  fur- 
nace that  the  fruit  dries  more  rapidly  in  the  center  of  the 
floor  than  about  the  sides.  To  regulate  this  and  make  the 
drying  as  uniform  as  possible,  a  '  deflector,'  consisting  of  a 
piece  of  sheet  iron  or  tin  several  feet  square,  is  attached  to  the 
floor  directly  above  the  furnace. 

"  Open  grates,  which  in  effect  are  furnaces  with  all  parts 


EVAPORATION    OF    FRUIT.  479' 

above  the  grates  removed,  are  used  occasionally  and  are  recom- 
mended by  some  because  they  require  less  fuel,  less  attention, 
to  firing,  and  will  dry  the  fruit  in  a  shorter  space  of  time. 
On  the  other  hand  so  much  dust  rises  from  them  that  they  are 
not  used  in  making  the  best  grade  of  fruit. 

"  In  some  respects  a  steam  system  is  the  most  satisfactory 
method  of  heating,  but  it  is  comparatively  little  used,  possi- 
bly due  to  the  larger  cost  of  installing  such  a  system.  In. 
kiln  evaporators  the  pipes  are  generally  placed  in  as  close 
proximity  to  the  floor  of  the  drying  room  as  is  convenient 
within  a  foot  or  even  closer.  That  every  steam  pipe  nearest 
the  floor  may  supply  the  greatest  amount  of  heat  it  should, 
have  its  own  return  to  the  main  return  of  the  system.  One 
inch  pipe  is  generally  used  for  such  systems.  No  very  defin- 
ite data  are  available  in  regard  to  the  amount  necessary  to 
supply  the  requisite  heat.  Several  kilns,  however,  which  are 
said  to  work  admirably  have  about  600  running  feet  of  pipe 
for  every  100  square  feet  of  floor  space.  One  half  of  this  is 
"  riser,"  the  other  half  "  return". 

"A  convenient  arrangement  for  an  evaporator  having  four 
or  five  kilps  is  as  follows :  The  kilns  are  built  of  brick  and 
the  apples  are  pared  in  an  adjacent  building.  A  bin  built  of 
slats  for  containing  the  apples  in  bulk  extends  the  entire  length 
of  the  building,  except  a  small  space  in  the  center  where  a  5- 
horsepower  gasoline  engine  is  located,  which  furnishes  power 
for  running  the  parers,  slicers  and  other  machinery.  The 
paring  table  is  on  the  opposite  side  of  the  building,  from  which 
the  fruit  is  taken  by  a  carrier  and  elevated  to  a  platform  which 
is  on  the  same  level  as  the  two  bleachers  between  the  evapor- 
ator and  the  paring  shed.  This  carrier  discharges  the  fruit 
into  trays  which  are  then  placed  by  hand  into  one  of  the 
bleachers  ;  from  this  they  are  taken  to  the  slicer,  located  in  a 
compartment  just  within  the  brick  portion  of  the  structure  and 
with  which  all  the  kilns  communicate,  thus  making  it  con- 
venient after  the  fruit  has  been  sliced. 

"  Other  large  establishments  have  the  kilns  arranged  in  a 


480  MANUFACTURE    OF    VINEGAR. 

series  situated  end  to  end.  The  fruit  is  pared  on  the  first 
floor  of  an  adjoining  structure  centrally  located  ;  then  elevated 
to  the  second  floor  which  is  on  the  same  level  as  the  kiln 
floors,  where  it  is  bleached  and  sliced.  Communication  is 
had  with  the  kilns  not  adjacent  to  the  floor  on  which  the  fruit 
is  sliced,  by  means  of  a  platform  extending  from  this  floor 
along  the  sides  of  the  kilns  and  on  the  same  level  as  the  kiln 
floors." 

For  commercial  purposes  the  selection  of  the  varieties  of 
fruit  to  be  evaporated  must  be  carefully  made.  This  ap- 
plies especially  to  apples  and  pears.  As  a  rule,  a  product  of 
high  grade  can  be  made  from  any  sort  which  has  a  firm  tex- 
ture and  bleaches  to  a  satisfactory  degree  of  whiteness.  Many 
evaporating  plants  have,  like  the  canning  establishments, 
•certain  favorites,  for  instance,  of  apples,  the  Baldwin,  Bell- 
flower,  Pippin,  Northern  Spy,  of  pears,  the  Bartlett,  Clapp's 
Favorite. 

Apples  are  pared  with  a  machine.  So  many  different  styles 
of  apple  parers  for  operating  either  by  hand  or  power  are  in 
the  market  that  it  is  difficult  to  say  which  is  the  best.  The 
more  recent  patterns  have  two  or  even  three  forks  for  holding 
the  apples  while  they  are  being  pared.  The  attendant  puts 
an  apple  on  one  of  the  forks  while  one  on  another  fork  is  being 
peeled.  The  apples  are  cored  in  the  same  operation  by  an 
Attachment  applied  to  the  paring  .machine  for  this  purpose. 
The  fruit  is  automatically  forced  from  the  fork  and  drops  to 
the  table  where  it  is  next  taken  in  hand  by  the  trimmers,  who 
•cut  out  with  a  straight-back  sharp-pointed  knife,  worm-holes, 
decayed  parts  and  other  blemishes. 

To  make  the  fruit  as  white  as  possible  it  is  usually  bleached 
by  subjecting  it  to  the  fumes  of  burning  sulphur  by  means  of 
a  contrivance  called  a  bleacher.  The  simplest  form  of  con- 
struction consists  of  a  box  sufficiently  long  to  meet  the  require- 
ments, placed  horizontally,  and  large  enough  in  cross  section 
to  admit  the  boxes  or  crates  in  which  the  fruit  is  handled. 
Rollers  are  placed  in  the  bottom,  on  which  the  crates  rest, 


EVAPORATION    OF    FRUIT.  481 

which  permit  them  to  be  moved  along  with  but  little  friction. 
The  crates  are  entered  at  one  end  of  the  bleacher,  those  pre- 
viously put  in  being  pushed  along  to  make  room  for  the 
following  ones.  The  sulphur  is  usually  burned  immediately 
below  the  point  where  the  fruit  is  put  into  the  bleacher.  A 
short  piece  of  stovepipe  is  placed  at  the  opposite  end  for  the 
escape  of  the  fumes  after  they  have  passed  through  the  bleacher. 

Another  simple  bleacher  in  which  the  fruit  is  handled  in 
bulk  (not  in  crates)  consists  essentially  of  a  large  square  box, 
the  interior  of  which  is  fitted  with  a  series  of  inclined  planes 
sloping  in  opposite  directions  to  prevent  the  fruit  from  dropping 
to  the  bottom  in  a  compact  mass.  The  fruit  is  usually  admit- 
ted at  the  top  directly  from  the  paring  table.  It  then  rolls 
from  one  inclined  plane  to  another  to  the  bottom,  where  there 
is  the  necessary  opening,  with  means  for  closing  it  tightly  to 
to  prevent  the  escape  of  the  sulphur  fumes,  for  removing  the 
fruit  when  it  is  bleached.  The  sulphur  is  burned  beneath 
the  lowest  inclined  plane. 

After  bleaching,  the  fruit  is  sliced  in  a  machine  called  a 
slicer,  of  which  there  are  various  styles.  In  general,  a  slicer 
consists  of  a  table  in  which  a  series  of  knives  is  so  arranged 
that  when  the  apples  are  carried  over  them  by  a  revolving 
arm  they  are  cut  -into  slices  about  J  inch  in  thickness.  In 
the  kiln-evaporator  the  sliced  fruit  is  evenly  spread  on  the 
floor  to  the  depth  of  from  4  to  6  inches.  It  is  a  common 
practice  to  treat  the  floor  of  the  kilns  occasionally  with  tallow 
to  prevent  the  fruit  from  sticking  to  it.  Sometimes  a  mixture 
of  equal  parts  of  tallow  and  boiled  linseed  oil  is  used  for  this 
purpose. 

No  definite  rules  can  be  given  regarding  the  temperature 
to  be  maintained  in  the  kiln,  this  being  largely  a  matter  of 
experience.  Some  operators  consider  150°  F.  a  suitable  tem- 
perature when  the  fruit  is  first  put  into  the  drying  compart- 
ment, dropping  to  about  125°  F.  as  the  drying  process  nears 
completion. 

The  fruit  while  drying  in  the  kiln  has  to  be  occasionally 
31 


482  MANUFACTURE  OF  VINEGAR. 

turned  to  prevent  it  from  burning  and  from  sticking  to  the 
floor.  For  the  first  five  or  six  hours  it  is  generally  turned 
every  two  hours  or  so,  and  more  frequently  as  it  becomes 
drier,  until  perhaps  it  may  require  turning  every  half-hour 
when  nearly  dry. 

When  drying  in  the  tower  evaporator  the  trays  or  racks 
must  not  be  too  heavily  loaded  with  fruit.  Stone-fruit  not 
freed  from  the  stones  is  placed  close  together  with  the  stem 
ends  upwards,  but  only  in  one  layer.  Plums  after  evaporat- 
ing are  generally  brought  into  a  bath  of  sugar-water  to  give 
them  a  lustrous  and  uniformly  dark  appearance.  For  this 
purpose  brown  sugar  is  dissolved  in  an  equal  quantity  of  hot 
water,  and  the  prunes  in  a  wire  basket  are  submerged  in  the 
bath  for  half  an  hour.  They  are  then  spread  out  upon 
hurdles  and  packed  when  perfectly  dry.  Quartered  or  halved 
stoned-fruit,  as  well  as  sliced  apples,  are  placed  close  together, 
edge  upward,  until  the  bottom  of  the  tray  is  covered.  Sliced 
pears  are  arranged  in  a  similar  manner.  Of  berries,  several 
layers  an  inch  deep  may  be  made,  but  they  must  be  covered 
with  tissue  paper.  Grapes  are  but  seldom  converted  into 
raisins  in  the  evaporating  apparatus,  because  the  process 
would  require  40  hours,  it  being  impossible  to  use  a  tempera- 
ture exceeding  167°  F.  Hence  it  is  considered  more  advan- 
tageous to  dry  grapes  in  the  sun.  .The  well-known  Malaga 
raisins  are  obtained  by  allowing  the  bunches  of  grapes  to  dry 
in  the  air.  They  are  dipped  for  an  instant  in  boiling  water 
to  sterilize  them  and  then  dried  on  straw  in  the  sun.  When 
the  grapes  have  shrunk  to  a  third  or  half  of  their  original 
volume,  the  best  are  packed  in  the  original  bunches,  but  the 
inferior  raisins  are  picked  from  the  stalks  before  packing. 
The  richer  the  grapes  are  in  sugar,  the  less  drying  they  need. 
In  Spain  the  bunches  are  dipped  into  a  boiling  lye  of  wood 
ashes  on  which  a  little  oil  is  floating.  They  are  dipped  and 
removed  as  quickly  as  possible,  and  the  trace  of  oil  that  ad- 
heres to  them  gives  a  characteristic  luster. 

Tomatoes  to  be  evaporated    in    the  tower  evaporator  are 


EVAPORATION    OP    FRUIT.  483 

peeled  but  not  sliced,  and  placed  close  together  in  one  layer 
in  the  trays.  Pumpkins  are  peeled  and  cut  in  pieces  two  or 
three  inches  thick.  For  several  years  a  flour  has  been  made 
from  the  dried  pieces,  which  serves  as  a  substitute  for  rice 
flour.  Sweet  potatoes  are  treated  in  a  similar  manner,  their 
flour  serving  as  a  substitute  for  chicory. 

Green  corn  is  first  steamed  on  the  ear  for  not  more  than  five 
minutes.  The  grains  are  then  picked  off,  placed  in  two-inch- 
deep  layers  in  the  trays  and  thoroughly  evaporated,  but  not 
at  too  high  a  temperature,  185°  to  194°  F.  being  sufficient. 
When  dry  they  are  rubbed  and  passed  through  a  fanning-mill 
to  remove  the  hulls  loosened  by  rubbing.  The  corn  is  packed 
in  boxes  holding  10,  20  and  50  Ibs.  each. 

The  following  must  also  be  steamed  before  evaporating : 
Green  peas  and  beans,  asparagus,  beets,  carrots,  lettuce,  cab- 
bage and  parsnips.  Vegetables  are  cut  up  with  a  cabbage- 
cutter,  and  roots  in  slices  like  apples. 

Onions  are  first  freed  from  their  external  red  or  yellow  peel 
and  then  cut  into  slices  one-fourth  inch  thick  with  a  cabbage- 
cutter.  The  slices  are  steamed  for  five  minutes  with  a  suitable 
steaming  apparatus,  which  is  best  effected  by  spreading  the 
slices  in  a  two-inch-deep  layer  in  the  trays,  placing  the  latter 
in  the  steaming  apparatus,  and  immediately  after  the  above- 
mentioned  time  in  the  evaporator.  They  are  packed  in  tin 
boxes  holding  50  Ibs.  each,  which  are  placed  in  a  wooden  box. 
By  evaporation,  100  Ibs.  of  onions  are  reduced  to  12  Ibs. 

Potatoes  must  be  thoroughly  washed.  This  is  best  effected 
in  a  cradle,  the  bottom  of  which  is  provided  with  wide  perfor- 
ations so  that  the  water,  constantly  pouring  in,  can  run  off 
quickly.  The  potatoes  are  then  placed  in  trays,  and  from 
four  to  six  of  the  latter,  according  to  the  size  of  the  steaming 
apparatus,  brought  into  the  boiler.  Steam  is  then  admitted, 
and  after  35  minutes  the  potatoes  are  taken  out,  care  being 
had,  however,  not  to  steam  them  too  much,  as  otherwise  they 
become  of  no  value  for  the  evaporating  process.  The  loosened 
peels  are  then  rubbed  off  with  the  hand,  and  the  peeled  pota- 


484  MANUFACTURE    OF    VINEGAR. 

toes  brought  into  a  press,  the  bottom  of  which  consists  of 
a  perforated  wooden  plate  or  of  woven  wires.  The  lid  must 
fit  tight  into  the  interior  walls  of  the  press,  so  that  the  entire 
mass  of  potatoes  falls  coarsely  crushed  through  the  bottom. 
The  crushed  potatoes  are  placed  in  layers  two  or  three  inches 
deep  in  the  trays  and  leveled  with  an  instrument  made  by 
driving  small  nails  into  a  board  so  that  their  points  project 
one-half  inch.  They  are  then  evaporated  at  not  too  high  a 
temperature — 185°  F.  is  sufficient — to  prevent  scorching; 
taking  care,  however,  to  dry  them  through.  The  evaporated 
mass  is  coarsely  ground  in  a  suitable  mill,  and  the  resulting 
flour  packed  in  zinc  canisters,  holding  28  and  56  Ibs.  each. 
Two  such  canisters  are  placed  in  a  wooden  box  and  are  then 
ready  for  shipment. 

It  is  of  the  utmost  importance  to  select  only  perfectly  sound 
potatoes  and  remove  all  which  sour  or  are  injured  in  any  other 
way  during  the  process.  Success  depends  on  the  rapidity  and 
regularity  from  the  commencement  to  the  end  of  the  process. 
All  potatoes  which  become  cold  before  being  brought  into  the 
evaporating  apparatus  are  worthless,  and  the  same  may  be 
said  of  those  which  have  been  steamed  too  long  ;  they  are  con- 
verted into  paste. 

Attention  may  be  drawn  to  a  sun-drying  apparatus  shown 
in  Fig.  101,  which  may  be  recommended  to  those  who  do  not 
wish  to  employ  artificial  heat,  and  are  forced  to  give  the 
preference  to  as  cheap  an  apparatus  as  possible.  The  appar- 
atus is  constructed  of  boards  and  window-glass.  The  board 
walls,  which  are  somewhat  inclined  outwardly,  project  above 
the  panes  of  glass  and  serve,  as  is  readily  seen,  for  catching 
the  rays  of  the  sun.  They  are  lined  inside  with  tin,  thus  be- 
coming reflectors.  The  side  door  serves  as  an  entrance  to  the 
apparatus  when  the  panes  of  glass  are  to  be  cleansed  or  repairs 
are  to  be  made  in  the  interior.  The  trays  containing  the  fruit 
are  pushed  in  from  the  back,  the  entrance  of  each  tray  being 
covered  by  a  wooden  flap.  According  to  the  size  of  the  ap- 
paratus two  or  three  rows,  each  consisting  of  twelve  trays,  are 


EVAPORATION    OF    FRUIT. 


485 


placed  alongside  each  other.  Above  the  uppermost  entrances 
for  the  trays  are  slides,  which  can  be  opened  or  closed  accord- 
ing to  whether  the  heat  in  the  interior  is  to  be  increased  or 
moderated. 

The  apparatus  stands  upon  a  turn-table,  so  that  the  front 
can  from  morning  to  evening  be  exposed  to  the  full  rays  of 
the  sun.  When  the  latter  no  longer  reach  the  apparatus  the 
reflectors,  which  are  hinged,  are  laid  over  the  panes  of  glass, 
which  prevents  the  radiation  of  heat,  and  protects  the  fruit 
from  dew. 

The  time  required  for  drying  fruit  in  this  apparatus  cannot 

FIG.  101. 


be  definitely  stated,  but  on  an  unclouded,  hot  summer  day, 
apples  pared  by  a  machine  can  be  dried  in  eight  hours.  The 
product  obtained  is  not  of  as  good  a  quality  as  evaporated 
fruit,  but  it  is  incomparably  superior  to  that  produced  by  the 
primitive  method  of  drying  in  the  open  air  or  in  the  oven. 

In  conclusion  it  remains  to  say  a  few  words  about  drying 
fruit  in  the  oven,  and  we  describe  the  French  method,  which 
is  decidedly  the  best,  as  proved  by  the  prunes  brought  into 
market  from  that  country.  The  prunes  having  been  sorted 
by  a  machine  into  three  qualities  are  placed  upon  trays  and 
exposed  to  the  sun  until  the  skin  commences  to  shrivel.  They 


486  MANUFACTURE    OF    VINEGAR. 

are  then  placed  in  a  bake-oven  previously  used  for  baking 
bread.  If  no  bread  is  to  be  baked,  the  oven  is  very  moderately 
heated  to  prevent  the  rapid  closing  of  the  pores  and  the  forma- 
tion of  a  crust  upon  the  surface.  They  are  allowed  to  remain 
in  the  oven  for  12  hours,  when  they  are  taken  out,  and  when 
perfectly  cold,  moistened  with  alum  water  and  replaced  in  the 
oven,  which  must  now  be  somewhat  hotter.  After  12  hours 
they  are  again  taken  out,  moistened  with  alum  water,  and  re- 
placed for  the  third  and  last  time,  together  with  a  dish  full  of 
water,  in  the  oven,  which  must  now  be  still  hotter  than  before. 
The  prunes  when  taken  from  the  oven  are  submerged  for  a 
short  time  in  a  bath  of  sugar-water,  and  are  then  packed  in 
boxes.  It  will  be  seen  that  this  process  is  quite  tedious,  and 
the  product  is  not  so  good  as  that  obtained  by  evaporation. 

Besides  prunes,  the  French  bring  into  the  market  dried 
pears,  which  have  also  become  celebrated.  The  process  is  as 
follows :  Fine  table-pears  are  pared,  quartered,  and  boiled  in 
sugar  syrup  for  five  minutes.  They  are  then  placed  in  a 
moderately  warm  oven,  where  they  remain  for  12  hours  ;  they 
are  then  taken  out,  allowed  to  cool  off,  and  replaced  in  the 
oven,  which  must  now  be  hotter  than  the  first  time,  until 
sufficiently  dried. 

The  French  method  can  be  recommended,  but  it  would  be 
still  better  if  it  wer£  executed  in  the  improved  manner  prac- 
ticed here  and  there  in  central  England  and  in  the  New  Eng- 
land States.  This  improvement  consists  in  the  previous  boil- 
ing of  the  fruit,  which  must,  however,  not  be  continued 
longer  than  five  minutes.  The  fruit  is  not  gradually  heated, 
but  submerged  in  boiling  water  for  five  minutes,  and,  with- 
out being  allowed  to  cool,  brought  at  once  into  a  moderately 
hot  oven.  Steaming  instead  of  boiling  the  fruit  is  still  bet- 
ter. It  should.be  exposed  to  the  steam  for  not  longer  than 
five  minutes,  and  must  then  as  quickly  as  possible  be  brought 
into  a  moderately  hot  oven. 


PREPARATION    OF    PICKLES    AND    MUSTARDS.  487 


CHAPTER  XXXIII. 

PREPARATION    OF    PICKLES    AND    MUSTARDS. 

Pickles. — Enormous  quantities  of  pickles  are  brought  into 
commerce,  especially  by  American  and  English  factories. 
The  most  remarkable  varieties  are  piccalilli  or  Indian  pickles, 
mixed  pickles  and  walnut  pickles.  The  packing  is  always  the 
same,  some  of  the  oldest  and  largest  English  factories  still  ad- 
hering to  stoneware  pots,  which  have  the  advantage  of  entirely 
excluding  the  light  from  the  product,  thus  contributing  to  its 
keeping  quality.  Both  the  French  and  Americans  use  glass 
bottles,  the  chief  difference  being  in  the  diameter  of  the  mouth, 
which  is  smaller  in  the  American  bottles.  The  latter  style  is 
to  be  preferred,  because  in  the  former  the  pickles,  when  fre- 
quently opened,  are  more  exposed  to  the  air  than  is  good  for 
them.  Stone  pots,  which  are  no  doubt  best  for  family  use,  are 
too  expensive  for  commercial  purposes,  not  only  as  regards 
the  first  cost,  but  also  on  account  of  their  weight,  which  in- 
creases the  cost  of  transportation.  The  bottles  are  always 
provided  with  neat  lables,  and  the  corks  generally  covered 
with  tin-foil. 

The  following  general  rules  apply  to  the  preparation  of 
pickles :  The  best  quality  of  fruit  must  be  gathered  at  the  right 
time,  washed  in  fresh  cold  well-water,  and  placed  for  some 
time  in  strong  brine.  They  are  then  laid  upon  fruit  hurdles 
to  completely  dry  in  the  air,  and  finally  brought  into  the  bottles, 
which  must  be  nearly  filled.  The  interspaces  are  then  filled 
up  with  hot-spiced  vinegar,  and  the  bottles  immediately  corked, 
and,  when  cold,  sealed.  Strong  vinegar  must  be  used,  the 
manufacturers  generally  employing  wine-vinegar,  known  in 
commerce  as  No.  24.  Fruit-vinegar,  clarified  and  spiced  and 
evaporated  to  three-fourths  its  volume,  also  answers  very  well. 
Pickles  for  immediate  use  are  soaked  in  hot  brine,  but  as  a 
commercial  article  they  must  be  treated  with  cold  brine  only. 


488  MANUFACTURE    OF    VINEGAR. 

Moreover,  hot  brine  must  not  be  used  for  vegetables  of  a  soft 
and  juicy  nature  such  as  cabbage  and  cauliflower  ;  and  besides, 
cold  or  only  slightly  heated  vinegar  should  be  poured  over 
such  articles.  Soft  and  delicate  fruits  must,  as  a  rule,  not  re- 
main as  long  in  the  brine  as  hard  and  coarse-fibred  ones  ;  and 
the  softest  are  most  advantageously  pickled  by  pouring  cold 
spiced  vinegar  over  them.  The  same  may  be  said  of  red  beets 
and  other  roots  which  are  cut  into  strips.  Sometimes  the  spice 
is  put  whole  into  the  bottle,  but  it  is  better  and  more  econom- 
ical to  bring  it  powdered  into  the  vinegar  while  heating  the 
latter,  or  if  the  vinegar  is  to  be  used  cold,  to  previously  boil 
the  powdered  spice  in  a  small  portion  of  the  vinegar,  and 
when  cold  add  it  to  the  rest.  The  spiced  vinegar  is  prepared 
as  follows : — 

To  1  quart  of  vinegar  add  2J  ounces  of  salt,  J  ounce  of 
black  pepper,  and  2J  ounces  of  ginger.  Let  the  mixture  boil 
up  once  or  twice  in  an  enameled  iron  pot,  filter  through  a 
flannel  cloth,  and  pour  the  liquid,  hot  or  cold,  over  the  fruit. 

For  a  more  strongly  spiced  vinegar  reduce  in  a  mortar  2 
ounces  of  black  pepper,  1  ounce  of  ginger,  and  J  drachm  of 
cayenne  pepper,  and  for  walnuts,  1  ounce  of  eschalots,  and  add 
to  the  mixture  in  a  stoneware  pot,  1  pint  of  vinegar,  and  tie 
up  the  pot  with  a  bladder.  Place  the  pot  for  three  days  near 
the  fire,  shaking  it  several  times,  and  then  pour  the  contents 
upon  the  fruits  by  allowing  it  to  run  through  a  filtering  cloth. 

In  the  preparation  of  pickles  the  use  of  metallic  vessels  must 
be  avoided,  the  vinegar  as  well  as  the  brine  dissolving  copper, 
brass,  and  zinc,  and  becoming  thereby  poisonous.  Ordinary 
earthen  pots  should  also  be  mistrusted.  Stoneware  pots,  which 
can  be  heated  in  a  water-bath  or  upon  a  stove,  are  best  for  the 
purpose.  Moreover,  air  and  light  must  be  kept  away  from  the 
pickles  as  much  as  possible,  and  they  should  be  touched  only 
with  wooden  or  bone  spoons.  An  essential  condition  for  suc- 
cess is  to  treat  the  fruits  immediately  after  being  gathered. 
The  method  of  some  manufacturers,  who  add  verdigris  to  the 
pickles  or  boil  the  vinegar  in  a  copper  boiler  until  it  is  suffi- 


PREPARATION    OP    PICKLES    AND    MUSTARDS.  4891 

ciently  "greenish"  to  communicate  its  color  to  the  product, 
cannot  be  too  strongly  condemned.  That  this  crime  against 
the  health  of  the  consumer  is  unfortunately  committed  to  a 
considerable  extent  is  conclusively  proved  by  numerous  chem- 
ical examinations  made  in  the  large  cities  of  Europe  and  the 
United  States,  and  undertaken  with  the  laudable  purpose  of 
bringing  the  adulterators  of  food  to  justice.  Many  of  the 
pickles  in  the  market  and  most  of  the  imported  canned  peas 
contain  copper,  and  this  notwithstanding  the  fact  that  there 
are  very  innocent  means  for  coloring  pickles  green,  it  being 
only  necessary  to  put  a  handful  of  spinach  or  grape  leaves  in 
the  boiling  vinegar,  which  acquires  thereby  a  green  coloration 
and  communicates  it  later  on  to  the  pickles. 

The  following  list  comprises  the  fruits  and  vegetables  which 
are  chiefly  used  for  the  preparation  of  pickles  in  factories : 

Barberries. — The  berries  are  gathered  before  they  are  ripe 
and  washed  with  salt  water.  The  vinegar  is  added  cold. 

Beans. — Cold  vinegar  is  poured  over  the  young  pods,  pre- 
viously soaked  in  cold  water. 

Cabbage,  Red  and  White. — The  heads  are  cut  up  into  fine 
strips,  which  are  placed  in  a  strong  brine  for  two  days,  then 
dried  upon  hurdles  for  twelve  hours,  next  brought  into  bottles, 
and  after  pouring  cold  vinegar  upon  them,  at  once  sealed  up. 

Cauliflower. — The  heads  are  broken  up  into  small  pieces, 
which  are  placed  in  brine,  and  finally  treated  with  hot 
vinegar. 

Cucumbers. — Young  cucumbers  are  placed  in  salt  water  for 
one  week.  The  brine  is  then  poured  off,  and  after  being  made 
boiling  hot  is  poured  back  over  the  cucumbers.  The  next 
day  the  cucumbers  are  dried  upon  a  sieve,  slightly  rubbed 
off  with  a  cloth,  and  then  boiling  vinegar  is  poured  over  them. 

Elderberry  Flowers. — The  umbels  are  gathered  just  before 
the  flowers  open,  and  treated  in  the  same  manner  as  cauli- 
flower. These  pickles  are  much  liked  in  England. 

English  Bamboo. — Young  elder  shoots  are  freed  from  the 
bark,  placed  in  a  brine  for  12  hours,  and  after  drying  brought 


490  MANUFACTURE    OF    VINEGAR. 

into  bottles  and  hot  vinegar  is  poured  over  them.     They  are 
highly  esteemed  as  an  addition  to  boiled  mutton. 

Gooseberries. — The  unripe  fruits  are  treated  like  cauliflower. 

Mixed  pickles  are  a  mixture  of  young,  tender  vegetables, 
preserved  separately,  each  at  the  proper  season,  and  stored  for 
mixing  later  on.  Small  gherkins,  young  corn  cobs,  pickling 
onions,  green  and  red  capsicums,  cauliflower,  young  beans, 
French  beans  and  French  carrots  form  the  chief  ingredients 
•of  this  mixture,  large  capers  and  salted  olives  being  also  used 
by  some  makers.  All  the  vegetables  are  highly  blanched 
and  left  to  stand  for  several  days  in  strong  brine  in  order  to 
ensure  their  keeping.  They  are  then  put  in  jars  with  good 
vinegar,  warmed  up  in  the  water-bath  and  closed  up.  The 
vegetables  may,  however,  be  stored  separately  in  brine  in  case 
•of  very  large  quantities. 

For  packing  in  bottles  and  other  containers,  good  4  per 
•cent,  wine-vinegar  is  used,  this  being  spiced  with  an  extract 
prepared  as  follows :  To  5  gallons  of  vinegar  add  36  ozs.  of 
black  pepper,  18  ozs.  of  ginger,  18  ozs.  of  salt,  10  ozs.  of 
pimento,  6  ozs.  of  white  pepper,  a  few  laurel  leaves  and  a  lit- 
tle tarragon,  allowing  the  mixture  to  stand  for  14  days  in  a 
warm  place  and  then  filtering.  The  filled  bottles  should  be 
^carefully  heated  on  the  water-bath  before  they  are  closed. 

Picalilti. — These  mixed  pickles  are  packed  with  the  follow- 
ing preparation  instead  of  vinegar:  Stir  2J  pounds  of  best 
English  mustard  powder  together  with  1  pint  of  best  olive  oil, 
and  to  this  add  2J  Ibs.  of  sugar,  £  Ib.  of  salt,  and  3  to  4  pints 
•of  good  vinegar,  with  J  pint  of  curry  vinegar.  The  curry 
vinegar  is  prepared  from  turmeric  3J  ozs.,  coriander  4  ozs., 
black  pepper  1  oz.,  ginger  1  oz.,  cardamoms  J  oz..  carraway 
-seeds  1  oz.,  cayenne  pepper  J  oz.,  all  powdered,  with  2J  gal- 
lons of  wine  vinegar.  When  all  has  been  thoroughly  mixed 
together,  the  sauce  is  strained  through  a  hair  sieve. 

Pickled  Gherkins. — Cut  off  the  stalks  and  sort  the  gherkins 
into  three  sizes.  Then  wash  them  carefully  and  pack  them 
into  suitable  clean  barrels.  Dill  may  be  used  as  spice  but 


PREPARATION    OF    PICKLES    AND    MUSTARDS.  491 

nothing  else.  Pour  over  them  a  pickle  consisting  of  12  per 
cent,  brine  containing  25  per  cent,  of  good  wine  vinegar. 
Place  the  barrels  in  the  sun  or  a  warm  place,  with  the  bung- 
holes  open,  so  as  to  quickly  start  a  slight  fermentation.  When 
this  has  run  its  course,  clean  up  the  barrels,  fill  them  to  the 
top  with  the  same  liquor,  if  necessary,  and  bung  them  down. 
For  use  the  gherkins  are  taken  out  of  the  barrels  and  packed 
with  fresh  wine  vinegar  spiced  with  tarragon.  If  these  small 
gherkins  are  to  be  kept  stored  in  the  barrels  for  a  long  time; 
the  fermented  pickle  should  be  drawn  off  and  replaced  by 
fresh  12  per  cent,  brine. 

Gherkins  in  Mustard. — Skin  and  cut  in  halves  large,  ripe 
gherkins,  remove  the  cores,  and  then  cut  them  into  long 
strips.  Place  the  latter  in  tubs,  sprinkle  well  with  salt  and 
allow  to  stand  for  several  days.  Then  wash  the  gherkins, 
pack  them  into  barrels  with  yellow  mustard  seed,  a  few  laurel 
leaves  and  white  pepper-corns,  small  onions,  sliced  horse- 
radish and  shredded  ginger.  Pour  in  sufficient  boiling  wine 
vinegar  to  cover  the  whole.  After  a  few  days  draw  off  the 
vinegar,  boil  it  up  and  return  it  to  the  barrels  and  heavily 
weight  the  latter.  The  vinegar  should  not  be  allowed  to  fall 
below  4  per  cent.,  otherwise  it  will  have  to  be  supplemented. 
In  3  to  4  weeks  the  gherkins  should  be  clear  and  translucent. 

Pickled  Mushrooms. — Clean  and  trim  off  at  the  bottom  young 
small  mushrooms  and  free  them  from  the  brown  skin.  Then 
wash  them  in  cold  water  and  carefully  dry  them.  Then  pack 
them  in  bottles  and  pour  boiling  wine  vinegar  over  them. 

Pickled  Onions. — Small  onions  are  peeled  and  hot  vinegar 
is  poured  over  them.  Sometimes  the  onions  are  placed  in 
brine  for  one  day. 

Pickled  Peaches. — The  fruits,  not  entirely  ripe,  are  treated 
like  cucumbers.*. 

Pickled  Peas — The  peas  are  treated  like  beans  and  cauliflower. 

Pickled  Tomatoes — must  not  be  entirely  ripe ;  they  may  be 
even  green  and  half  grown.  They  are  pickled  in  the  same 
manner  as  cucumbers. 


492  MANUFACTURE    OF    VINEGAR. 

Pickled  Walnuts. — Place  the  young,  soft  nuts  in  strong  brine 
for  one  week,  then  dry  upon  a  sieve  and  pour  hot  vinegar 
over  them.  A  better  method  is  to  expose  the  walnuts  after 
they  have  been  in  the  brine  for  nine  days,  upon  a  cloth,  to  the 
sun  until  they  are  black,  and  then  put  them  into  bottles,  which 
are  filled  up  with  hot  vinegar.  These  pickles  are  much  liked 
with  fish,  and  when  well  sealed  and  stored  in  a  dark  place 
keep  for  ten  years.  If  they  are  to  be  used  in  the  first  three 
months  after  being  made,  the  brine  must  be  heated  for  one 
hour. 

Mustard. — Mustard  of  commerce  is  the  seed,  whole  or  ground, 
of  several  species  of  the  genus  Brassica,  cruciferous  plants, 
which  grow  wild  and  are  cultivated  under  various  conditions. 
The  two  common  varieties  are  the  black  or  brown  mustard, 
which  has  a  very  small  seed,  and  furnishes  the  most  aroma, 
and  the  white,  which  is  two  or  three  times  as  large,  often  used 
in  the  whole  condition  in  pickles  and  ground,  either  by  itself 
or  oftener  in  mixture  with  the  brown  seed,  for  the  purpose  of 
obtaining  the  desirable  qualities  of  both. 

The  most  rational  manner  of  preparing  mustard  for  table 
use  has  been  introduced  into  the  English  factories.  The  seed 
is  freed  from  the  husk,  ground  to  flour,  and  the  fat  oil,  which 
can  be  used  as  an  illuminating  oil,  pressed  out.  Generally 
speaking,  the  preparation  of  mustard  consists  in  several  times 
grinding  in  a  mill  a  mixture  of  white  and  brown  mustard 
with  an  addition  of  wine-must,  either  fresh  or  strongly  boiled 
down,  or  of  wine  vinegar,  until  it  forms  a  moderately  fine  or 
very  fine  pasty  mass,  and  adding  different  substances  as  a 
seasoning.  In  the  Diisseldorf  mustard  the  seasoning  consists 
of  cinnamon,  cloves,  and  sugar ;  in  the  Frankfort  mustard  of 
cloves,  allspice,  and  sugar ;  in  the  English  mustard,  of  wheat 
flour,  common  salt  and  pepper:  and  in  French  mustard,  of 
tarragon,  ginger,  cinnamon,  thyme,  marjoram,  onions,  garlic, 
cloves,  etc.  An  addition  of  flour  is  most  generally  made,  as 
it  modifies  the  sharpness  of  the  mustard  and  holds  the  mass 
better  together.  The  quantity  of  the  constituents  varies,  the 


PREPARATION    OF    PICKLES    AND    MUSTARDS.  493 

usual  proportions  being  from  20  to  30  per  cent,  of  white, 
and  5  to  10  per  cent,  of  brown,  mustard,  1  to  2  per  cent,  of 
common  salt,  £  to  J  per  cent,  of  pulverized  spices,  and  40  to 
50  per  cent,  of  must  or  vinegar.  According  to  the  English 
method  the  use  of  mustard-seed  freed  from  oil  is  recommended. 
In  the  following  a  few  special  receipts  are  given  : 

Gumpoldskirchner  Must-mustard. — -Evaporate  30  quarts  of 
freshly  pressed  wine-must  to  one-half  its  volume  over  a  mod- 
erate fire,  dissolve  in  it  5  Ibs.  of  sugar,  and  strain  the  whole 
over  2  or  3  roots  of  horseradish  cut  in  thin  slices.  Then  add 
in  the  form  of  fine  powder,  cardamoms  0.35  oz.,  nutmeg  0.35 
oz.,  cloves  0.63  oz.,  cinnamon  1  oz.,  ginger  1  oz.,  mustard- 
seed,  grourtd  and  freed  from  oil,  brown  6  Ibs.  and  white  11 
Ibs.  Grind  the  whole  several  times  in  a  mill  and  strain. 

Moutard  des  Jesuites. — Make  a  paste  of  12  sardines  and  280 
capers  and  stir  it  into  53  ozs.  of  boiling  vinegar,  and  mix  with 
it  ground  mustard-seed  freed  from  oil,  brown  5J  ozs.  and 
white  14J  ounces. 

French  Mustard. — Ground  mustard  2  Ibs.,  and  J  oz.  each  of 
fresh  parsley  and  tarragon,  both  cut  up  fine,  are  thoroughly 
mixed  together;  further  1  clove  of  garlic,  also  add,  cut  up  very 
fine,  12  salted  anchovies.  Grind  the  mixture  very  fine,  add  the 
required  must  and  1  oz.  of  pulverized  common  salt,  and  for 
further  grinding  dilute  with  water.  To  evaporate  the  water 
after  grinding  the  mustard,  heat  an  iron  red-hot  and  cool  it 
off  in  the  mixture,  and  then  add  wine-vinegar  of  the  best 
quality. 

Ordinary  Mustard. — I.  Stir  gradually  1  pint  of  good  white 
wine  into  8  ozs.  of  ground  mustard-seed,  add  a  pinch  of  pul- 
verized cloves,  and  let  the  whole  boil  over  a  moderate  fire. 
Then  add  a  small  lump  of  white  sugar,  and  let  the  mixture 
boil  up  at  once. 

II.  Pour  \  pint  of  boiling  wine-vinegar  over  8  ozs.  of  ground 
mustard-seed  in  an  earthen  pot,  stir  the  mixture  thoroughly, 
then  add  some  cold  vinegar,  and  let  the  pot  stand  over  night 
in  a  warm  place.  The  next  morning  add  \  Ib.  of  sugar,  j 


494  MANUFACTURE    OF    VINEGAR. 

drachm  of  pulverized  cinnamon,  J  drachm  of  pulverized 
cloves,  1J  drachms  of  pepper,  some  cardamom  and  nutmeg, 
half  the  rind  of  a  lemon  and  the  necessary  quantity  of  vine- 
gar. The  mustard  is  now  ready,  and  is  kept  in  pots  tied  up 
with  bladder. 

III.  Pound  to  a  paste  in  a  mortar  the  flesh  of  a  salt  herring, 
and  2  ozs.  of  capers,  and  mix  this  with  2  ozs.  of  pulverized 
white  sugar  and  13  ozs.  of  ground  mustard-seed  ;  then  pour 
If  pints  of  boiling  wine  vinegar  over  it,  stir,  and  let  the 
whole  stand  near  a  fire  for  several  hours.  Finally  add  £  pint 
of  boiling  vinegar,  stir  thoroughly  and  pour  the  mustard  into 
glass  bottles. 

Frankfort  Mustard. — Mix  1  Ib.  of  white  mustard-seed,  ground, 
a  like  quantity  of  brown  mustard-seed,  8  ozs.  of  pulverized 
sugar,  1  oz.  of  pulverized  cloves,  2  ozs.  of  allspice,  and  com- 
pound the  mixture  with  white-wine  or  wine-vinegar. 

Wine  Mustard. — Ground  mustard-seed,  white,  23  ozs.,  brown 
12  ozs.,  common  salt  2|  ozs.,  wine  vinegar  8J  ozs.,  a  like 
quantity  of  white  wine,  and  water  16  ozs. 

Aromatic  or  Hygienic  Mustard. — Ground  mustard-seed,  white, 
23  ozs.,  brown  12  ozs.,  wine  vinegar  17J  ozs.  Extract  all- 
spice 0.35  oz.,  cassia,  white  pepper,  and  ginger,  of  each  0.17 
oz.,  with  alcohol  1}  ozs.,  and  water  8J  ozs.,  add  3J  ozs.  of 
common  salt  and  a  like  quantity  of  sugar,  filter  the  whole 
and  add  it  to  the  mustard. 

Dusseldorf  Mustard. — Ground  mustard-seed  freed  from  oil, 
brown  3  ozs.,  white  SJ  ozs.,  boiling  water  26J  ozs.,  wine 
vinegar  18  ozs.,  cinnamon  0.17  oz.,  cloves  0.1  oz.,  sugar  11 
ozs.,  white  wine  18  ozs. 

Sour  Dusseldorf  Mustard. — Fill  2  casks  with  vinegar,  steep 
in  one  of  the  casks  2  Ibs.  of  origan  leaves,  and  in  the  other 
an  ordinary  bucket  full  of  onions  cut  up,  and  let  them  digest 
for  2  days.  Then  bruise  44  Ibs.  of  white  mustard-seed 
and  66  Ibs.  of  brown ;  put  this  in  a  vat  and  add  1  Ib.  of  pul- 
verized cloves,  1J  Ibs.  of  pulverized  coriander  seed,  and  4J 
gallons  of  each  of  the  prepared  vinegars.  Stir  the  whole  thor- 


PREPARATION    OF    PICKLES    AND    MUSTARDS.  495 

oughly  and  grind  it  twice  in  a  mill.  To  every  gallon  of  this 
add  and  mix  thoroughly  with  it,  1  Ib.  of  salt  dissolved  in  1 
quart  of  the  onion  vinegar. 

Sweet  Kremser  Must-mustard. — Ground  mustard-seed,  brown 
10  Ibs.,  white  5  Ibs.,  is  intimately  mixed  with  3  Ibs.  of  fresh- 
ly-pressed must,  and  boiled  down  to  the  desired  consistency. 

Sour  Kremser  Must-mustard. — Boil  to  a  stiff  paste  15  Ibs.  of 
brown  mustard  ground,  and  5  Ibs.  of  white  mustard  ground, 
together  with  4  Ibs.  of  must,  and  after  cooling  stir  in  4  Ibs.  of 
vinegar. 

Moutarde  de  maille. — Cut  up  8  ozs.  of  fresh  tarragon  leaves 
without  the  stems,  2^  ozs.  of  basil,  2  ozs.  of  bay  leaves  and  4 
ozs.  of  rocambole  (a  spice  of  garlic).  Place  these  ingredients- 
in  a  glass  alembic,  pour  2  J  quarts  of  strong  wine-vinegar  over 
them,  and,  to  allow  the  vapors  to  escape,  tie  up  the  mouth  of 
the  alembic  with  a  piece  of  perforated  moist  bladder.  Place 
the  alembic  upon  hot  sand  for  4  days,  then  filter  the  fluid 
first  through  linen  arid  then  through  blotting  paper.  Add  to 
this  aromatic  vinegar,  1  oz.  of  common  salt,  then  stir  it  into  a 
thick  paste  with  ground  brown  mustard-seed,  and  keep  the 
the  mustard  in  earthenware  jars  tied  up  with  bladder. 

Moutarde  aux  epices  is  prepared  by  extracting  18  ozs.  of 
tarragon  leaves,  7  ozs.  of  basil,  If  ozs.  of  bay  leaves,  3J  ozs. 
of  white  pepper,  If  ozs.  of  cloves,  and  0.35  oz.  of  mace  with 
vinegar  and  mixing  the  extract  with  mustard  prepared  in  the 
ordinary  manner  from  ground  mustard-seed,  brown  44  Ibs., 
white  11  Ibs.,  and  vinegar  8J  Ibs. 

Moutarde  Aromatisee. — Boil  ground  mustard-seed,  brown  22 
Ibs.,  white  44  Ibs,  with  9  Ibs.  of  vinegar,  and  add  oil  of  tarra- 
gon 1  oz.,  oil  of  thyme  J  oz.,  oil  of  mace  0.35  oz.,  and  oil  of 
cloves  0.17  oz.,  all  previously  dissolved  in  very  strong  vinegar. 

English  Mustard. — Ground  mustard-seed  9  Ibs.,  wheat  flour 
9  ozs.,  common  salt  1}  Ib.,  cayenne  pepper  2|  ozs.,  and  as 
much  vinegar  and  water  as  required. 


496  MANUFACTURE    OF    VINEGAR. 

CHAPTER  XXXIV. 

PRESERVATION  OF  MEAT,  FISH  AND  EGGS. 

Appert's  Method  of  Canning  Meats. — This  method  consists  in 
soldering  up  the  food  in  tin  cans  with  great  care,  and  then 
heating  the  cans  for  considerable  time  in  water.  The  cans 
used  are  either  cylinders  or  four-sided  cases.  Although  the 
latter  do  not  waste  so  much  space  as  the  former  when  packed 
with  others,  the  cylinders  are  generally  preferred,  they  being 
•easier  to  make  by  machinery  and  much  easier  to  solder  up. 
The  duration  of  the  heating  depends  on  the  size  of  the  can, 
for  every  part  of  its  contents  must  be  kept  at  the  temperature 
of  boiling  water  for  a  sufficient  time.  Meat  is  a  bad  conduc- 
tor of  heat  and  it  takes  "considerable  time  before  the  contents 
of  larger  cans  are  heated  through  and  through  to  212°  F. 

The  time  required  for  the  purpose  can  only  be  learned  by 
experience.  Insert  in  one  of  the  cans  a  thermometer  so  that 
the  bulb  is  exactly  in  the  centre  of  the  can,  and  observe  re- 
peatedly the  time  which  elapses  between  when  the  water  com- 
mences to  boil  and  the  moment  at  which  the  mercury  rises  to 
212°  F. 

In  placing  the  prepared  meats  in  the  cans,  the  pieces  should 
be  so  arranged  as  to  leave  but  few  interspaces  between  them, 
&nd  the  cans  should  be  filled  as  full  as  possible,  so  that  but 
little  air  remains  in  them.  Immediately  after  the  cans  are 
filled,  the  lids  are  soldered  on.  When  a  sufficient  number  of 
•cans  have  been  soldered,  they  are  at  once  heated  to  the  tem- 
perature of  boiling  water.  Heating  by  steam  is  more  suitable 
•and  less  troublesome  than  by  water.  For  this  purpose  the 
•cans  are  so  arranged  in  a  chamber  that  the  steam  can  circu- 
late freely  round  each  one,  the  bottom  layer  of  cans  resting 
•on  a  lattice  bottom.  The  steam  enters  the  chamber  below 
this  lattice  bottom  and  escapes  through  an  aperture  on  the 
tipper  side  of  the  chamber.  Below  the  lattice  bottom  is  a 
trap  for  drawing  off  the  condensed  water.  At  first  the  steam 


PRESERVATION    OF    MEAT,    FISH    AND    EGGS.  497 

is  admitted  at  a  pressure  of  two  to  three  atmospheres.  The 
steam  condenses  on  the  cold  cans  and,  when  condensation  has 
ceased,  the  blow-off  cock  is  shut,  and  the  passage  of  steam  is 
continued  until  the  contents  of  the  cans  have  been  heated  to 
212°  F.  The  time  required  for  this  purpose  depends  on  the 
size  of  the  chamber,  the  number  of  cans  in  it,  the  quantity 
and  temperature  of  the  steam  introduced,  etc.  Iii  all  cases, 
whether  heating  is  done  by  water  or  by  steam,  care  must  be 
had  to  only  gradually  increase  the  heat  to  give  the  heated 
oxygen  time  to  be  absorbed  by  the  meat.  By  heating  too 
rapidly  it  may  happen  that,  in  consequence  of  the  great  pres- 
sure exerted  by  the  strongly  heated  air  upon  the  sides  of  the 
cans,  the  soldered  places  may  become  defective,  and  the  cans 
be  spoiled. 

When  heating  has  been  successfully  finished,  i.  e.,  when  all 
the  oxygen  has  been  absorbed  and  the  cans  remain  perfectly 
tight,  it  will  frequently  be  observed  that,  after  cooling,  the 
bottoms  of  the  cans  bulge  inward,  though  they  were  perfectly 
flat  previous  to  heating.  This  is  a  favorable  indication  of 
successful  preservation  of  the  contents,  because  the  oxygen 
contained  in  the  box  being  completely  fixed  to  the  meat,  the 
tension  of  the  other  enclosed  gas  (nitrogen)  is  considerably 
decreased  in  cooling,  which  causes  the  slight  bulging  inward 
of  the  bottoms.  When,  on  the  other  hand,  it  is  observed  that 
the  bottoms  of  cans  which  have  been  stored  for  some  time 
bulge  outward,  it  is  an  indication  that  the  contents  are  in  a 
state  of  decomposition  produced  by  the  ferments  contained  in 
them  not  having  been  destroyed.  In  consequence  of  decom- 
position gases  are  evolved  which  accumulate  more  and  more, 
and  by  their  pressure  force  the  bottoms  to  bulge  outward  and 
finally  burst  the  cans. 

The  object  to  be  attained  in  operating  according  to  Appert's 
method,  is  to  leave  as  little  air  as  possible  in  the  cans.  This 
object  may  be  reached  in  various  ways.  With  meat,  which  is 
to  be  canned  together  with  the  broth,  the  smaller  cans  are 
closed  in  the  usual  manner  by  soldering,  and  a  small  hole  is 
32 


498  MANUFACTURE    OF    VINEGAR. 

punched  in  the  lids.  When  the  cans  have  been  sufficiently 
heated  and  the  steam  escapes  from  the  small  holes,  the  latter 
are  closed  by  a  drop  of  solder.  For  larger  cans  sufficient 
water  is  added. to  the  broth  to  fill  the  cans  nearly  to  the  rims. 
They  are  then  closed  in  the  usual  manner,  a  small  hole  is 
punched  in  the  lids  and  the  cans  are  heated  as  long  as  a  cur- 
rent of  steam  escapes  from  the  holes,  when  the  latter  are 
closed  by  a  drop  of  solder.  In  consequence  of  heating,  the 
expanded  air  escapes  first  from  the  cans,  the  last  portions  being 
displaced  by  the  steam.  After  closing  the  small  holes  and 
cooling,  the  free  spaces  in  the  cans  are  almost  free  from  air. 
When  a  hole  is  punched  in  a  can  a  peculiar  hissing  sound  is 
heard,  which  is  produced  by  the  air  rushing  into  the  can. 

Appert's  method  is  adapted  for  all  kinds  of  meat,  whether 
stewed  or  roasted,  with  or  without  broth.  To  save  space  the 
bones  of  larger  animals  are  removed  and  the  cans  are  packed 
with  pieces  of  meat.  Smaller  animals,  for  instance,  poultry, 
are  cut  up  and  then  canned. 

Corned  beef  is  prepared  by  Appert's  method.  The  meat  is 
freed  from  fat  and  cut  into  slices.  The  latter  are  then  packed 
closely  interstratified  with  a  little  salt  into  cans  of  a  truncated 
pyramidal  shape.  The  cooking  is  done  with  high-pressure 
steam,  and  causes  the  slices  to  cohere  into  a  solid  mass. 

Meat  Biscuit  according  to  Gallamond. — The  preparation  of 
this  product  embraces  three  operations :  Preparation  of  the 
bouillon,  preparation  of  the  dough,  and  baking  of  the  biscuit. 

1.  Preparation  of  the  bouillon.  Bring  56  Ibs.  of  beef  and  24 
quarts  of  water  in  a  boiler,  add,  tied  in  a  linen  bag,  thyme, 
bay  leaves,  two  nutmegs,  cloves,  pepper,  cinnamon  or  ginger, 
and  22  Ibs.  of  vegetables  (carrots,  turnips,  leek).  After  boil- 
ing for  four  hours,  remove  the  bones  from  the  meat,  divide 
the  latter  into  small  pieces,  return  them  to  the  bouillon  and 
continue  boiling  for  1J  hours  longer.  The  contents  of  the 
boiler  are  then  of  the  consistency  of  a  very  thin  paste.  Dissolve 
in  this  paste  about  \  Ib.  of  rock  candy,  which  is  claimed  to  in- 
crease the  keeping  qualities  of  the  biscuit.  In  the  manner 


PRESERVATION    OF    MEAT,    FISH    AND    EGGS.  499 

above  described  about  11  quarts  of  very  concentrated  broth 
are  obtained,  which  contains  all  the  soluble  parts  and  the  fibrin 
of  48  Ibs.  of  meat  (8  Ibs.  being  lost  in  the  form  of  bones,  sin- 
ews, etc.). 

2.  Preparation  of  the  dough.     110  Ibs.  of  wheat  flour  are  in- 
corporated by  kneading  with  the  11   quarts  of  bouillon.     The 
dough  is  very  solid  and  is  cut  up  into  biscuits,  generally  237. 

3.  Baking  the  Biscuit.     The  biscuits  remain  in  the  oven  for 
1J  hours.     The  composition  of   100  parts  of  this  biscuit   is 
about  as  follows :  Dry  flour,  76.45  ;  dry  meat,  5.79  :  fat,  6.27  ; 
dry  vegetables,  2.77  ;  spices  and  sugar,  0.92  ;  water,  7.80. 

Soup  Tablets.  For  the  preparation  of  soup  tablets  it  is  first 
of  all  necessary  to  extract  the  soluble  matters  from  the  meat. 
The  proper  plan  to  do  this  is  to  keep  the  meat  in  cold  water 
and  then  to  heat  it  gradually  and  not  to  a  temperature  so 
high  as  to  coagulate  the  albumen.  If  the  meat  is  plunged 
from  the  start  in  boiling  water,  the  outside  of  it  is  made  im- 
pervious by  the  coagulation  of  the  albumen  and  the  soluble 
constituents  are  only  imperfectly  extracted  even  by  long  boil- 
ing. The  meat  should  be  scrupulously  cleaned  from  fat.  It  is 
then  minced  in  a  mincing  machine  or  cut  up  small  with  a 
chopper,  and  steeped  in  water  which  should  not  be  too  hard 
and  is  gradually  brought  to  a  temperature  not  exceeding  140 °F. 
Heating  is  kept  up,  whilst  constantly  stirring,  for  several 
hours.  When  working  on  a  large  scale  a  mechanical  stirrer 
should  be  used.  The  proportion  of  water  to  meat  should  be 
two  parts  to  one  by  weight.  After  heating  for  three  hours 
nothing  will  be  left  undissolved  but  worthless  fibrin.  The 
temperature  is  then  raised  to  about  194°  F.  The  liquid, 
previously  clear,  then  becomes  thick,  and  a  scum  rises  to  the 
surface,  both  these  appearances  being  due  to  the  coagulation 
of  the  albumen.  The  liquid  thus  prepared  may  be  stored  by 
bringing  it,  while  still  hot,  into  vessels,  filling  them  quite  full 
and  closing  them  air-tight.  The  liquid  will  keep  for  many 
months. 

For  the  preparation  of  soup  tablets,  the  liquid  is  mixed  with 


500  MANUFACTURE    OP    VINEGAR. 

about  1  lb.  of  salt  for  every  100  Ibs.  of  meat  used  and  filtered 
through  several  folds  of  linen.  The  filtrate  is  evaporated  in 
very  shallow  thvplate  pans,  without,  however,  allowing  it  to 
boil,  till  a  sample  becomes  hard  when  cold.  The  entire  mass 
is  then  cast  into  molds.  When  properly  made  soup  tablets 
are  usually  of  a  pale  brown  color  and  give  a  perfectly  clear 
solution  in  water,  having  the  taste  of  fresh  beef  tea. 

Beef  extract. — This  product  is  made  at  Fray  Bentos  in 
Uruguay,  by  the  following  method.  The  meat  from  the  cattle 
of  the  grass  plains  of  the  pampas  is  freed  from  bones  and  fat, 
and  minced.  The  paste  is  mixed  with  water  and  subjected 
to  great  hydraulic  pressure.  The  concentrated  solution  of  the 
soluble  constituents  of  the  meat  thus  obtained  is  at  once 
boiled  to  coagulate  the  albumen.  The  clear  liquid  is  then 
evaporated  in  vacuum  pans  till  the  mass  on  cooling  is  of  a 
semi-solid  consistency.  When  prepared  in  this  manner  the 
extract  contains  no  gelatine  and  forms  a  perfectly  clear  solution 
with  water.  The  absence  of  gelatine  and  fat  makes  the  extract 
so  unalterable  that  a  pot  of  it  can  be  left  for  as  long  as  desired 
in  a  damp  mouldy  room  without  undergoing  change. 

Quick  Salting  of  Meat  by  liquid  pressure. — This  process  is 
especially  applicable  to  the  preservation  of  large  masses.  A 
reservoir  of  concentrated  brine  is  placed  on  a  high  level,  at 
least  30  feet  above  the  room  where  the  process  is  worked.  A 
pipe  brought  down  from  the  reservoir  is  connected  by  a  length 
of  rubber  tube  with  an  iron-pointed  pipe.  This  pipe  is  about 
8  inches  long,  is  provided  with  a  tap  and  has  numerous  holes 
bored  in  it  towards  the  point.  If  this  point  is  inserted  into  the 
middle  of  a  piece  of»meat  and  the  tap  is  opened,  the  hydrostatic 
pressure  causes  the  brine  to  penetrate  the  meat  completely  in 
a  very  few  minutes.  The  pieces  impregnated  in  this  manner 
are  placed  for  about  24  hours  in  concentrated  brine,  and  the 
meat  loses  no  nutritive  matter  as  it  is  already  thoroughly 
penetrated  with  brine.  The  pieces  are  then  simply  dried  or 
slightly  smoked. 

Quick  Process  of  Smoking  Meat. — This  process  is  based  upon 


PRESERVATION    OF    MEAT,    FISH    AND    EGGS.  501 

the  fact  that  crude  wood  vinegar  (pyrol igneous  acid)  as  ob- 
tained iu  the  destructive  distillation  of  wood  contains  creosote 
as  well  as  acetic  acid  and  water.  It  has  a  strong  smoky 
smell  and  is  a  powerful  antiseptic.  The  meat  is  for  a  few 
seconds  dipped  in  the  fluid,  allowed  to  drain  off  and  then 
hung  up  to  dry.  The  room  in  which  the  work  is  done  should 
be  warm  enough  for  the  fat  of  the  meat  to  become  soft,  the 
absorption  of  the  wood  vinegar  being  thereby  facilitated. 
When  the  meat  has  absorbed  the  acid  it  is  again  dipped  two 
or  three  times  in  the  wood  vinegar,  and  then  left  to  itself  for 
48  to  60  hours  when  it  may  be  considered  as  thoroughly 
cured.  To  give  the  cured  meat  the  aromatic  taste  of  juniper, 
a  small  quantity  of  oil  of  juniper  is  dissolved  in  the  wood 
vinegar  diluted  with  water.  A  fluid  of  the  following  com- 
position yields  excellent  results  : 

Crude  wood  vinegar 50  gallons. 

Water ...*.....   ...    .    .    100      " 

Oil  of  juniper .  I    .   .    .  V  .   .    .    .    .      2£       " 

Although  the  acetic  acid  contained  in  the  wood  vinegar 
acts  as  a  preservative,  the  greater  portion  of  it  is  lost  by  evap- 
oration, and  hence  a  fluid  may  suitably  be  used  which  con- 
tains only  a  small  quantity  of  wood  vinegar,  but  a  larger 
quantity  of  the  actually  effective  creosote.  Such  a  fluid  may 
be  prepared  as  follows  : 

Water 500  parts  by  weight. 

Creosote 5     "              " 

Crude  wood  vinegar 50     " 

Oil  of  juniper 5     "               c< 

Dissolve  the  creosote  in  the  wood  vinegar,  dissolve  in  this 
solution  the  oil  of  juniper,  and  pour  the  fluid  in  a  thin  jet, 
with  constant  stirring,  into  the  water. 

Curing  may  also  be  very  rapidly  effected  by  bringing  the 
meat  into  a  smoke-house  connected  with  a  well-drawing  chim- 
ney, and  placing  on  the  floor  of  the  smoke-house  shallow 
dishes  containing  a  mixture  of 


502  MANUFACTURE    OF    VINEGAR. 

Wood  vinegar 50  parts. 

Creosote 10     " 

Water 50      <k 

Place  a  large  bath  sponge  in  each  dish,  and  conduct  a  cur- 
rent of  warm  air  over  the  dishes. 

By  the  current  of  warm  air  the  fluid  absorbed  by  the 
sponges  is  evaporated,  and  curing  rapidly  effected. 

Preparation  of  Powdered  Meat. — An  excellent  product — a 
kind  of  pemmican — is  obtained  by  a  process  patented  by 
Hassal.  The  meat  used  for  the  purpose  should  be  as  free  as 
possible  from  fat,  veins  and  sinews,  fat  being  particularly  sub- 
ject to  decomposition.  The  meat  is  cut  up  in  a  mincing 
machine  to  a  paste,  and  the  latter  is  spread  out  in  thin  layers 
on  tin  plate  and  dried  in  a  drying  room,  a  very  convenient 
way  being  to  force  hot  air  over  the  layers  by  means  of  a  fan. 
The  temperature  should  never  exceed  140°  F.,  otherwise  the 
albuminous  constituents  of  the  meat  coagulate  and  become 
insoluble.  Drying  is  continued  at  between  122°  and  140°  F. 
till  the  meat  is  considerably  reduced  in  volume  and  forms  a 
crusty  mass.  The  latter  is  next  reduced  to  powder  in  a  mill, 
dried  again,  and  then  brought  into  metal  cans  or  paper  cylin- 
ders lined  with  tin-foil.  A  soup  of  excellent  taste  and  quality 
is  obtained  from  this  meat  powder  by  simmering  for  some 
time  in  water  at  between  122°  and  140°  F. 

Preservation  of  Fish. — In  order  to  obtain  a  good  product,  fish 
which  are  to  be  preserved  in  oil  should  be  treated  a  few  hours 
after  having  been  caught.  The  fish  should  be  carefully  cleaned, 
the  entrails  taken  out,  the  tails  cut  off,  and  eventually  the  heads 
also,  as  they  impart  a  bitter  taste  to  the  fish.  Finally  the  fish 
are  for  a  short  time  laid  in  brine.  They  are  then  taken  out, 
thoroughly  rinsed  in  clean  water,  laid  upon  grates  to  drain,  and 
finally  dried  in  the  air,  or,  when  this  is  impossible  on  account 
of  unfavorable  weather,  in  ovens  of  special  construction,  in 
which  they  remain  until  they  feel  perfectly  dry  and  solid. 
They  are  then  laid  upon  shallow  wire  sieves,  and  boiled  in 
olive  oil  until  done.  The  boiler  is  generally  heated  by  steam. 


PRESERVATION    OF    MEAT,    FISH    AND    EGGS.  503 

The  oil  should  have  a  temperature  of  310°  to  338°  F.,  and, 
according  to  the  size  of  the  fish,  45  to  80  seconds  are  required 
for  boiling.  When  boiling  is  finished,  the  sieves  with  the  fish 
are  taken  from  the  oil,  and  after  draining  off  and  drying,  the 
fish  are  packed,  according  to  sizes,  in  tin  cans.  The  latter  are 
then  filled  with  oil,  closed  by  soldering  on  the  lids,  and, 
according  to  Appert's  method,  again  boiled.  Separate  pieces 
of  larger  fish  are  treated  in  the  same  manner. 

According  to  Appert's  method,  all  kinds  of  fish,  lobster, 
crabs,  oysters,  etc.,  can  be  preserved  by  preparing  them  in  the 
same  manner  as  for  immediate  consumption,  then  putting 
them  in  tin  cans,  closing  the  latter  by  soldering,  and  heating 
them  in  hot  water  or  by  steam,  so  that  the  contents  are 
exposed  to  a  temperature  of  at  least  212°  F. 

Preservation  of  Eggs. — Eggs  are  frequently  preserved  by 
means  of  lime  water,  which,  to  be  sure,  is  one  of  the  most 
convenient,  but  at  the  same  time  one  of  the  worst  methods, 
the  eggs  acquiring  the  disagreeable  taste  of  lime. 

To  prevent  eggs  preserved  in  lime  water  from  acquiring  a 
disagreeable  taste  of  lime,  Kubel  recommends  lime  water  of 
1.0029  specific  gravity,  and  to  dissolve  in  it  6  per  cent,  of  con- 
mon  salt,  so  that  the  fluid  shows  a  specific  gravity  of  1.042. 
Perhaps  a  6  per  cent,  common  salt  solution  without  lime  water 
would  answer  as  well. 

A  good  preserving  fluid  is  commercial  glycerin  diluted  with 
half  its  volume  of  well  water.  Salicylic  acid  is  also  very  use- 
ful for  the  purpose.  Prepare  a  mixture  of  2  quarts  of  water 
and  1  quart  strong  alcohol,  add  7  ozs.  of  glycerin,  and  dissolve 
in  this  fluid  as  much  crystallized  salicylic  acid  as  will  dissolve 
in  it.  Bring  the  eggs  to  be  preserved  into  the  fluid,  allow  them 
to  remain  for  one  hour,  and  then  let  them  dry,  placing  them 
for  this  purpose  in  a  frame  of  boards  or  sheet  zinc  provided 
with  holes,  one  egg  being  placed  in  each  hole.  In  drying, 
the  water  and  alcohol  rapidly  evaporate,  and  the  salicylic  acid 
dissolved  in  them  would  separate  in  crystals  upon  the  surface 
of  the  eggs.  However,  the  glycerin  does  not  evaporate,  as  it 


504  MANUFACTURE    OF    VINEGAR. 

possesses  the  property  of  vigorously  absorbing  water  from  the 
air,  and,  besides,  dissolves  salicylic  acid.  Hence  a  fluid  is 
formed  which  consists  of  a  saturated  solution  of  salicylic  acid 
in  glycerin  and  fills  the  pores  of  the  eggs. 

The  expense  of  preserving  eggs  by  this  method  is  very  small, 
since  a  fluid  containing  2  Ibs.  of  salicylic  acid  in  solution 
suffices  for  many  thousands  of  eggs.  In  order  not  to  waste 
any  of  the  preserving  fluid,  the  drippings  from  the  eggs  al- 
ready treated  may  be  collected  in  a  vessel  and  again  used. 

Eggs  preserved  in  this  manner  may  be  kept  for  many 
months  at  the  ordinary  temperature  of  living-rooms  without 
the  slightest  alteration. 

The  result  of  the  competition  for  prizes  offered  by  the  Asso- 
ciation of  Poultry  Breeders  of  the  Province  of  Saxony,  Prussia, 
has  shown  that  water-glass  (silicate  of  soda)  is  an  excellent 
preservative  for  eggs.  The  first  prize  was  awarded  to  a  com- 
petitor who  had  used  the  following  process:  The  eggs,  which 
should  be  perfectly  clean,  were  placed  in  a  can  filled  with  a  10 
per  cent,  solution  of  silicate  of  soda  and  the  can  was  closed 
air-tight.  The  solution  was  once  renewed  during  the  preserv- 
ing time  of  six  months.  The  temperature  of  the  storage  room 
on  the  hottest  day  was  77°  F.  In  appearance  the  eggs  could 
not  be  distinguished  from  fresh  eggs.  The  yolk  and  white 
were  perfect,  and  the  taste  excellent. 

A  simple  method  of  preserving  eggs  by  means  of  silicate  of 
soda  is  as  follows  :  Immerse  the  eggs  in  a  solution  of  silicate  of 
soda  for  about  10  minutes  by  floating  a  board  on  top  of  them. 
Then  remove  them  and  stand  them  up  with  their  small  ends 
in  little  holes  in  a  shelf  for  two  days,  when  they  can  be  packed 
for  storage  or  transit.  The  silica  of  the  silicate  of  soda  is  set 
free  by  the  carbon  dioxide  of  the  air  and  thenfforms  with  the 
lime  of  the  egg-shell  a  glassy  sheet  of  calcium  silicate  which 
closes  all  the  pores. 

The  competition  previously  referred  to  has  further  shown 
that  the  breed  of  chickens  is  without  influence  upon  the  pre- 
serving capacity  of  the  eggs,  which,  however,  appears  some- 


PRESERVATION    OF    MEAT,    FISH    AND    EGGS.  505- 

what  affected  by  the  feed.  As  is  well  known,  eggs  of  chickens 
which  run  free  and  subsist  chiefly  on  animal  food — worms, 
insects,  etc. — have  a  reddish-yellow  yolk,  while  chickens  fed 
chiefly  with  grain  lay  eggs  with  a  pale  yellow  yolk.  The 
latter  have  a  finer  taste  than  the  former.  Exporters  also 
assert  that  eggs  with  a  red-yellow  yolk  do  not  keep  so  well, 
and  in  Russia,  for  instance,  are  for  this  reason  excluded  as- 
much  as  possible  from  export.  To  recognize  the  color  of  the 
yolk,  hold  the  egg  before  the  light. 


APPENDIX. 


TABLE  I. — Hehner's  Alcohol  Table. 


.s3 

S3 

J5,c 

S3 

s3 

13 

.s3 

S3 

rt 

§1 

al 

rt 

00  O 

11 

« 

§1 

11 

rt 

M  o 

1  8 

|> 

>  rt 

H 

fr 

•g-a 

H 

>, 

<L>  P-M 

£  « 

o« 

>, 

1-3 

w 

1 

!l 

K| 

,£>    3 

*j"0 

1 

*j 

j'S 

>>2 
•51 

'> 

rt 

a 

fc,s 

;      ^3,3 
1       *J   O 

4 

*J9 

'> 
• 
M 

"1 

rf 

*-'  9 

** 

§3 

u 

it 

8| 

o  w 

§1 

K 

H 

§1 

lo^ 

«'! 

u  w 

c  S 
8*« 

P 

»•* 

S° 

B 

So 

^ 

1-8 

s^ 

S^ 

P 

5° 

53° 

W 

PH 

PH 

en 

Pi 

PH 

ca 

:      P- 

PH 

W 

PH 

PH 

I.CXX)O 

0.00 

0.00 

0.9969 

i-75 

2.20 

0.9938 

3-53 

442 

0.9907 

5-44 

6.78 

8 

1.81 

2.27 

7 

3-59 

4-49 

6 

5-50 

6.86 

0.9999 

0.05 

0.07 

7 

1.87 

2-35 

6 

3-65 

4-56 

5 

5.56 

6.94 

8 

O.I  I 

0.13 

6 

1.94 

2.43 

5 

3-71 

4-63 

4 

5.62 

7.01 

7 

0.16 

O.2O 

5 

2.00 

2.51 

4 

3.76 

4.71 

3 

5.69 

7.09 

6 

0.21 

O.26 

4 

2.06 

2.58 

3 

3-82 

4.78 

2 

5-75 

7.17 

5 

0.26 

0.32 

3 

2.  1  1 

2.65 

2 

3-88 

4.85 

I 

5.81 

7-25 

4 

0.32 

0.40 

2 

2.17 

2.72 

I 

3-94 

4-93 

O 

5.87 

7-32 

3 

0.37 

0.46 

I 

2.22 

2.79 

O 

4.00 

5.00 

2 

0.42 

0-53 

o 

2.28 

2.86 

0.9899 

5-94 

7.40 

I 

0.47 

O.6O 

0.9929 

4.06 

5.08 

8 

6.00 

7.48 

0 

0.53 

0.66 

0.9959 

2-33 

2-93 

8 

4.12 

5.16 

7 

6.07 

7-57 

2-39 

3.00 

7 

4.19 

5-24 

6 

6.14. 

7.66 

0.9989 

0.58 

0-73 

7 

2-45 

3-07 

6 

4-25 

5-32 

5 

6.21 

7-74 

8 

0.63 

0.79 

6 

2.5I 

3-14 

5 

4-31 

5-39 

4 

6.28 

7.83 

7 

0.68 

0.86 

5 

2-57 

3.21 

4 

4-37 

5-47 

3 

6.36 

7.92 

6 

0.74 

0-93 

4 

2.61 

3-28 

3 

4.44 

5-55 

2 

6.43 

8.01 

5 

0.79 

0.99 

3 

2.65 

3-35 

2 

4-5° 

5-63 

j 

6.50 

8.10 

4 

0.84 

.06 

2 

2.71 

3-42 

I 

4-56 

5-71 

0 

6.57 

8.18 

3 

0.89 

•13 

I 

2.78 

3-49 

O 

4.62 

5.78 

2 

0-95 

.19 

0 

2.84 

3-55 

0.9889 

6.64 

8.27 

I 

1.  00 

.26 

0.9919 

4.69 

5.86 

8 

6.71 

8.36 

0 

i.  06 

•34 

0.9949 

2.89 

3-62 

8 

4-75 

5-94 

7 

6.78 

8-45 

8 

2.94 

3-69 

7 

4.81 

6.O2 

6 

6.86 

8.54 

0.9979 

.12 

.42 

7 

3.00 

3.76 

6 

4.87 

6.10 

5 

6-93 

8.63 

8 

7 

.I9 
•25 

•49 

•57 

6 

5 

3.06 
3.12 

3.83 
3-90 

5 
4 

4.94 
5.00 

6.17 
6.24 

4 
-     3 

7.00 
7.06 

8.72 
8.80 

6 

•31 

.65 

4 

3.18 

3.98 

3 

5.06 

6.32 

2 

7-!3 

8.88 

5 

•37 

•73 

3 

3-24 

4-05 

2 

5.12 

6.40 

I 

7.19 

8.96 

4 

.44 

.81 

2 

3-29 

4.12 

I 

5-J9 

6.48 

O 

7.27 

9.04 

3 

•50 

1.88 

I 

3.35 

4.20 

O 

5-25 

6.55 

2 

.56 

1.96 

O 

3.41 

4.27 

0.9879 

7-33 

9-13 

I 

.62 

2.04 

0.9909 

5-3i 

6.63 

8 

7.40 

9.21 

0 

.69 

2.12 

0.9939 

3-47 

4-34 

8 

5-37 

6.71 

7 

7-47 

9-29 

1 

(506) 


APPENDIX. 

TABLE  I. — Continued. 


507 


rt 

[Mg 

11 

rt 

•il 

|1 

-j 

3   O 

rt 

il 

11 

F—        tJ 

ITS 

'3  Jj 

•£  ™ 

£> 

'!*« 

f-S 

'C  J 

f  "3 

V 

5 

n*  3 

£  = 

rt 

.a  Ja 

^  "2 

£                    -03 

J?  "3 

nj 

jQ    3 

^  "S 

!*; 

§1 

§1 

M 

^"3 

il 

M 

~j 

jl 

So 

|| 

il 

l& 

5^ 

$° 

i 

5^ 

S^ 

S 

5° 

P 

S^ 

£ 

£ 

Pu 

C/3 

PH 

* 

* 

b 

O> 

0.9876 

7-53 

9-37 

0.9836 

10.38 

12.87 

0.9796 

13.46 

16.61 

0.9756 

16.77 

20.61 

5 

9-45 

5 

10.46 

12.96 

5 

13-54 

16.70 

5 

16.85 

20.71 

4 

7^67 

9-54 

4 

10.54 

13.05 

4 

13.62 

1  6.80 

4 

16.92 

20.80 

3 

7-73 

9.62 

3 

10.62 

13.15 

3 

13.69 

16.89 

3 

17.00 

20.89 

2 

7.80 

9.70 

2 

10.69 

13.24 

2 

13.77 

16.98 

2 

17.08 

20.99 

I 

7.87 

9.78 

I 

10.77 

13.34 

I 

13-85 

17.08 

I 

17.17 

21.09 

O 

7«93 

9.86 

0 

10.85 

13.43 

0 

13.92 

17.17 

0 

17-25 

21.19 

0,9869 

8.00 

9-95 

0.9829 

IO.92     13.52 

0.9789 

14.00 

17.26 

0.9749 

17.33 

21  29 

8 

8.07 

10.03 

8 

u.oo  13.62 

8 

14.09 

17-37 

8 

17.42 

21.39 

7 

8.14 

10.12 

7 

11.08  13.71 

7 

14.18 

17.48 

7 

17.50 

21.49 

6 

8,21 

10.21 

6 

11.15 

13.81 

6 

14.27 

17-59 

6 

17.58 

21.59 

5 

8.29 

10.30 

5 

11.23  J3-90 

5 

14.36 

17.70 

5 

17.67 

21.69 

4 

8.36 

10.38 

4 

11.31 

13.99 

4 

14.45 

17.81 

4 

17.75 

21.79 

3 

8.43 

10.47 

3 

11.38 

14.09 

3 

T4-55 

17.92 

3 

17.83 

21.89 

2 

8.50 

10.56 

2 

11.46  14.18 

2 

14.64 

18.03 

2 

17.92 

21.99 

I 

0 

8.57 
8.64 

10.65 
10.73 

I 

O 

11-54 
11.62 

14.27 
14.37 

0 

M.73 
14.82 

18.14 
18.25 

I 
0 

1  8.00 
1  8.08 

22.O9 
22.18 

0.9859 

8.71 

10.82 

0.9819 

11.69 

14.46 

0.9779 

14.91 

18.36 

0-9739 

18.15 

22.27 

8 

8.79 

IO.9I 

8 

11.77 

14.56 

8 

15.00 

18.48 

8 

18.23 

22.36 

7 

8.86 

11.00 

7 

11.85 

14.65 

7 

15.08 

18.58 

7 

18.31 

22.46 

6 

8-93 

11.08 

6 

11.92  14.74 

6 

15.17 

18.68 

6 

18.38 

22.55 

5 

9.00 

11.17 

5 

12.COJ  14.84 

5 

18.78 

5 

18.46 

22.64 

4 

9.07 

11.26 

4 

1  2.08    14.93 

4 

15-33 

18.88 

4 

18.54 

22-73 

3 

9.14 

n-35 

3 

12.15  ^-o2 

3 

15.42 

18.98 

3 

18.62 

22.82 

2 

9.21 

11.44 

2 

12.23  I5«12 

2 

15-50 

19.08 

2 

18.69 

22.92 

I 

9.29 

11.52 

I 

12.31 

15.21 

I 

15.58 

19.18 

I 

18.77 

23.01 

0 

9.36 

11.61 

O 

12.38 

15-30 

0 

J5-67 

19.28 

O 

18.85 

23.10 

0.9849 

9-43 

11.70 

0.9809 

12.46 

15.40 

0.9769 

15.75 

19.39 

0.9729 

18.92 

23.19 

8 

9.5° 

11.79 

8 

12.54  15.49 

8 

15.83 

19.49 

8  19.00 

23.28 

7 

9-57 

11.87 

7 

12.62 

15-58 

7 

15.92 

«9-59 

7(  19.08 

23.38 

6 

9.64 

11.96 

6 

12.69 

15.68 

6 

16.00 

19.68 

6 

19.17 

23.48 

5 

9.71 

12.05 

5 

12.77 

15-77 

5 

1  6.08 

19.78 

5 

19.25 

23.58 

4 

3 

9-79 
9.86 

12.13 

12.22 

4 
3 

12.85 
12.92 

15.86 
15.96 

4 
3 

16.15 
16.23 

19.87 
19.96 

4 
3 

19.33 
19.42 

23-68 
23.78 

2 

9-93 

12.31 

2 

13.00 

16.05 

2 

16.31 

20.06 

2 

19.5° 

23.88 

I 

IO.OO 

I2.4O 

I 

13.08 

16.15 

I 

16.38 

20.15 

I 

19.58 

23.98 

0 

10.08 

12.49 

0 

13.15 

16.24 

O 

16.46 

20.24 

O 

19.67 

24.08 

0.9839 

10.15 

12.58 

0.9799 

13.23 

16.33 

0-9759 

16.54 

20.33 

0.9719 

19.75 

24.18 

8 

10.23 

12.68 

8 

I3-3I 

16.43 

8 

16.62 

20.43 

8 

19-83 

24.28 

7 

10.31 

12.77 

7 

13.38  16.52 

7 

16.69 

20.52 

7 

19.92 

24.38 

1 

508 


APPENDIX. 

TABLE  I. — Concluded. 


rt 

II 

I* 

8 

|| 

J2  8 

^ 

4-*O 

II 

CC 

sj 

§1 

>*,            i    "^  *^5 

83 

bk, 

^ 

'«~ 

"o  *~* 

>•> 

"o  *"" 

|£  ^ 

§ 

I"" 

>   ^ 

•g 

S     « 

>  ^ 

C 

^    03 

^   ^ 

1 

.a  « 

b! 

1 

*| 

.03 

g 

^3 

^3 

5 

j£»{j 

^3 

M 

*J   3 

4-1      3 

to 

4-J  "O 

M 

^j  *o 

«"s 

M 

•  *o 

5JJB^ 

U 

§] 

1C     • 

^u! 

§-§ 

slj* 

§•« 

51 

•-  O 

5  « 

S-I 

Is 

*l 

u   « 
£"8 

n 

i* 

1* 

£° 

^° 

P 

CA) 

I* 

ff- 

0.9716 

20.00 

2448 

0.9699 

21.38 

26.13 

0.9682 

22.69 

27.68 

0.9666 

23.92 

29.13; 

5 

20.08|  24.58 

8  21.46 

26.22 

I 

22.77 

27.77 

5 

24.00 

29.22 

4 

20.17    24.68 

7  21.54 

26.31 

o 

22.85 

27.86 

4 

24.08 

29.31 

3 

20.25    24.78 

6  21.62 

26.40 

3 

24.I5 

29.40 

2 

20.33,  24  88 

5!  21.69 

26.49 

0.9679 

22.92 

27.95 

2 

24.23 

29.49 

I 

20.42!  24.98 

4 

21.77 

26.58 

8 

23.00 

28.04 

I 

24.31 

29.58 

O 

20.50 

25.07 

3|  21.85 

26.67 

7 

23.08 

28.13 

0 

24.38 

29.67 

2!  21.92 

26.77 

6 

23.15 

28.22 

0.9709 

8 

20.58 
20.67 

25.27 

i 

o 

22.00 
22.08 

26.86 
26.95 

5 
4 

23.23 
23.31 

28.31 
28.41 

0.9659 

8 

24.46 
24.54 

29.76 

29.86 

7 

20.75 

25-37 

3 

23-38 

28.50 

7 

24.62 

29-95 

6 

20.831  25.47 

0.9689 

22.15 

27.04 

2 

23.46 

28.59 

6 

24.69 

30.04 

5 

20.92 

25^7 

8,  22.23  27.13 

I 

23.54 

28.68 

5 

24.77 

30.13 

4 

2I.OO 

25.67 

7  22.31  27.22 

O 

23.62 

28.77 

4 

24.85    30.22 

3 

2  1.  08 

25.76 

6;  22.38  27.31 

3 

24.92 

30.3! 

2 

21.15 

25.86 

5 

22.46  27.40 

0.9669 

23.69 

28.86 

2 

25.00 

30.40 

I 

21.23 

25-95 

4 

22.54 

27.49 

8 

23-77 

28.95 

O 

2I.3IJ  26.04 

3!  22.62 

27-59 

7 

23.85 

29.04 

APPENDIX. 


509 


TABLE  II. —  Which  indicates  the  specific  gravity  of  mixtures 
of  alcohol  and  water. 

The  figures  in  the  column  to  the  left  show  the  per  cent,  by  volume  of  alcohol;  the 
figures  in  the  column  to  the  right  give  the  specific  gravities  which  correspond  to 
the  content  of  alcohol  at  60°  F. 


1 

Specific 

1 

Specific 

1 

Specific 

1 

Specific 

fl 

gravity  at 

0 

gravity  at 

•L 

gravity  at 

3 

>"o 

gravity  at 

,0  8 

rCt    <J 

•&  8 

•°  8 

+z  "c3 

*-    ^ 

.j'w 

**  "rt 

g-s 

60°  F. 

§° 

60°  F. 

§o 

60°  F. 

§0 

60°  F. 

Jl 

| 

1 

1 

I 

0.9985 

26 

0.9698 

51 

0.9323 

76 

0.8747 

2 

0.9970 

27 

0.9688 

52 

0.9303 

77 

0.8720 

3 

0.9956 

28 

0.9677 

53 

0.9283 

78 

0.8693 

4 

0.9942 

29 

0.9666 

54 

0.9263 

79 

0.8665 

5 

0.9928 

30 

0.9655 

55 

0.9242 

80 

0.8639 

6 

0.9915 

31 

0.9643 

56 

0.9221 

81 

0.86II 

7 

0.9902 

32 

0.9631 

57 

0.9200 

82 

0.8583 

8 

0.9880 

33 

0.9618 

58 

0.9178 

83 

0-8555 

9 

0.9878 

34 

0.9605 

59 

0.9156 

84 

0.8526 

10 

0.9866 

35 

0.9592 

60 

0.9134 

85 

0.8496 

ii 

0.9854 

36 

0-9579 

61 

0.9112 

86 

0.8466 

12 

0.9843 

37 

0.9565 

62 

0.9090 

87 

0.8436 

13 

0.9832 

38 

0.955° 

63 

.0.9067 

88 

0.8405 

14 

0.9821 

39 

0-9535 

64 

0.9044 

89 

0.8373 

'5 

0.9812 

40 

0.9519 

65 

0.9021 

90 

0.8339 

16 

0.9800 

41 

0.9503 

66 

0.8997 

91 

0.8306 

17 

0.9790 

42 

0.9487 

67 

0.8973 

92 

0.8272 

18 

0.9780 

43 

0.9470 

68 

0.8949 

93 

0.8237 

19 

0.9770 

44 

0.9452 

69 

0.8925 

94 

0.8201 

20 

0.9760 

45 

o-9435 

70 

0.8900 

95 

0.8164 

21 

0.9750 

46 

0.9417 

0.8875 

96 

0.8125 

22 

0-9740 

47 

0-9399 

72 

0.8850 

97 

0.8084 

23 

09729 

48 

0.9381 

73 

0.8825 

98 

0.8041 

24 

0.9719 

49 

0.9362 

74 

0.8799 

99 

0-7995 

25 

0.9709 

5° 

0.9343 

75 

0-8773 

100 

0.7946 

510 


APPENDIX. 


TABLE  III. — Proportion  between  per  cent,  by  weight  and  by  vol- 
ume of  alcoholic  fluids  at  59°  F. 
(According  to  Stampfer.) 


ioo  liters  of 

| 

In  ioo 

In 

ioo  liters  of 

1 

In  ioo 

In 

the  alcoholic 

rt 

•g  <S 

kilgr. 

i  kl. 

the  alcoholic 

2 

IS 

kilgi. 

lid. 

liquid 

Efl 

o 

ul 

liquid 

o 

t«  C 

contain  — 

10 

Is 

contain  — 

<C 

j=  £ 

L 

°1 

1 

g-13 

5| 

V-   ^ 

'* 

o'l 

*£  ^4 

!^<U 

Of  the  alcoholic 

if 

Of  the  alcoholic 

Alco- 

•5- "5 

J'fl) 

liquid 

Alco- 

° 7  "S 

liquid 

hol, 

Water, 

v^o 

I 

are  contained 

hol, 

Water, 

So 

11 

are  contained 

hers. 

liters. 

° 

alcohol,  kilogr. 

liters. 

liters. 

Q 

alcohol,  kilogr. 

IOO 

0.00 

o  7951 

79-51 

100.00 

79-51 

49 

54-70 

0.9366 

93-66 

41-59 

38.96 

99 

1.28 

0.8000 

80.00 

98.38 

78.71 

48 

55-68 

9385 

93.85 

40.66 

38.16 

98 

2-54 

8046 

80.46 

96-83 

77.92 

47 

56.66 

9403 

94-03 

39-74 

37-37 

97 

3-77 

8089 

80.89 

95-35 

77.12 

46 

57-64 

9421 

94.21 

38.82 

36.57 

96 
95 

4-97 
6.16 

8130 
8169 

81.30 
81.69 

93-89 
92.45 

76.33 
75-53 

45 
44 

58.61 
59-58 

9439 
9456 

94-39 
94.56 

37-9° 
37-— 

35-78 
34-98 

94 

7-32 

8206 

82.06 

91.08 

74-74 

43 

60.54 

9473 

94-73 

36.09 

34-I9 

93 

8.48 

8242 

82.42 

89.72 

73-94 

42 

61.50 

949° 

94.90 

35-iS. 

33-39 

92 

9.62 

8277 

82.77 

88.37 

73-15 

62.46 

9506 

95-o6 

34-30 

32.60 

91 

10.76 

.  8311 

83.11 

87.04 

72.35 

40 

63.42 

0.9522 

95-22 

33-4° 

31.80 

90 

1.88 

0-8344 

83.44 

85.74 

39 

64-37 

9538 

95.38 

32.52 

31.01 

88 

3.01 
4.12 

8377 
8409 

83-77 
84.09 

84.74 
83.22 

70.76 
69.97 

38 
37 

65-32 
66.26 

9553 
9568 

Q5-53 
95-68 

31-63 
30-75 

30.21 

29.42 

87 

5-23 

8440 

84.40 

81.96 

36 

'67.20 

9582 

95-82 

29.88 

28.62 

86 

6.32 

8470 

84.70 

80.72 

68.38 

35 

68.12 

9595 

95-95 

29.01 

27.83 

85 

7.42 

8500 

85.00 

79-51 

67.58 

34 

69.04 

9607 

96.07 

28.14 

27.03 

84 
83 

8.52 
19.61 

8530 
8559 

85-30 
85.59 

78.29 
77.09 

66.78 
65.99 

33 
32 

•  69.96 
70.89 

9620 
9633 

96.20 
96.33 

27.27 
26.41 

26.24 
25-44 

82 

20.68 

8588 

85.88 

75-91 

65.10 

3i 

71.80 

9645 

96-45 

25-56 

24.65 

Si 

21.76 

8616 

86.16 

74-75 

64.40 

30 

72.72 

0.9657 

96.57 

24.70 

23-85 

80 

^2.83 

0.8644 

86.44 

73-59 

63.67 

29 

73.62 

9668 

23-85 

23.06 

79 

23.90 

8671 

86  71 

72.43 

62.81 

28 

74-53 

9679 

96.79 

23.— 

22.26 

78 
77 

24.96 
26.03 

8698 
8725 

86.98 
87-25 

70.16 

62.02 
61.22 

:? 

75-43 
76.33 

9690 
9701 

96.90 
97.01 

22.16 
21.31 

21.47 
20.67 

76 

27.09 

8752 

87.52 

69.04 

60.43 

25 

77-23 

9711 

97.11 

20.47 

19.88 

75 

28.15 

8778 

87.78 

67-93 

59-63 

24 

78-13 

9721 

97-21 

19-63 

19.08 

74 

29.20 

8804 

88.04 

66.82 

58.84 

23 

79.02 

973* 

97-31 

18.79 

18.29 

73 

30.26 

8830 

88.30 

65.72 

58.04 

22 

79.92 

9741 

97.41 

17.96 

17.49 

72 

31-30 

8855   88.55 

64.64 

57-25 

21 

.80.81 

9751 

97-5 

17.12 

16.70 

71 

32.35 

8880  !  88.80 

63.68 

56.45 

20 

81.71 

0.9761 

97-6 

16.29 

15.90 

7° 

33-39 

0.8905  :  89.05 

62.50 

55-66 

19 

82.60 

9771 

97-7 

I5-46 

15.11 

69 

34-44 

8930  i  89.30 

61.43 

54-86 

18 

83.50 

9781 

97-8 

14.63 

I4-3I 

68 

35-47 

8954  !  89.54 

60.38 

54-07 

J7 

84.39 

9791 

97-9 

13.80 

67 

36.51 

8978  |  89.78 

59-33 

53-27 

16 

85.29 

9801 

98.0 

12.98 

12  72 

66 

37-54 

9002 

90.02 

58.29 

52.48 

15 

86.19 

9812 

98.1 

12.15 

11  -93 

65 

38-58 

9026 

90.26 

57-35 

51.68 

87-09 

9822 

98.22 

"•33 

11.13 

64 

39-6o 

9°49 

90.49 

56-23 

50.89 

13 

88.—    9833 

98.33 

10.51 

10.34 

63 

40-63 

9072  90.72 

55-21 

50.09 

12 

88.90  :  9844 

98.44    9.69 

9-54 

62 

41.65 

9095  90.95 

54-20 

49-30 

II 

89.80  I  9855 

98.55    8.78 

8-75 

61 

42-67 

9117  91.17 

53-19 

48.50 

10 

90.72   0.9867 

98.67 

8.06 

7-95 

60 

43-68 

0.9139  91.39 

52.20 

47-71 

g 

91.62    9878 

98.78 

7.24 

7.16 

59 
58 

44.70 
45-72 

9161  ;  91.61 
9183  :  91.83 

51.20 
50.21 

46.92 
46.12 

7 

92.54 

93-45 

9890 
9902 

98.90 
99.02 

6.43 
5.62 

6.36 
5-57 

57 

46.73 

9205  92.05 

49.24 

45-32 

6 

94-38 

99*5 

4.81 

4-77 

56 

55 

47-73 
48.74 

9226  ]  92.26 
9247  92.47 

48.26 
47.40 

44-53 
43-73 

5 
4 

95-30 
96.24 

9928 
9942 

99-28 
99.42 

4-— 
3.20 

3-98 

54 

49-74    9267  '  92-67 

46.33 

42.94 

3 

97-77 

9956 

99.56 

2.40 

2-39 

53 

50.74 

9288  92.88 

45-37 

42.14 

2 

98.11 

997° 

99.70 

i.  60 

i-59 

52 

51-74 

93°8  !  93.08 

44.41 

I 

99-05 

9985 

99.85 

0.80 

0.80 

51 

5273 

9328    93.28 

43-47 

40-55 

0 

IOO.OO 

1.  0000 

100.00 

0.00 

0.00. 

50 

53.72   0.9348  j  93.48 

42-53 

39-76 

APPENDIX. 


511 


TABLE  IV. — The  actual  content  of  alcohol  and  water  in  mixtures 
of  both  fluids,  and  the  contraction  which  takes  place  in  mixing. 


ioo  volumes  contain 

ioo  volumes  contain 

volumes  — 

volumes  — 

Specific 

Contrac- 

Specific 

Contrac- 

gravity. 

tion- 

gravity. 

tion. 

Alcohol. 

Water. 

Alcohol. 

Water. 

1.  0000 

0 

100.000 

O.OOO 

0.9323 

51 

52.705 

3.705 

0.9985 

I 

99.055 

°55 

°3 

52 

711 

70 

2 

98.111 

in 

0.9283 

53 

50.716 

7l6 

56 

3 

97.176 

176 

63 

54 

49.722 

722 

42 

4 

96.242 

242 

42 

55 

48.717 

717 

28 

5 

95-307 

307 

21 

56 

47.712 

712 

15 

6 

94.382 

382 

O.92OO 

57 

46.708 

708 

02 

7 

93458 

458 

0.9178 

58 

45.693 

693 

0.9890 

8 

92.543 

543 

56 

59 

44.678 

678 

78 

9 

91.629 

629 

34 

60 

43.664 

664 

66 

10 

90.7H 

7H 

12 

61 

42.649 

649 

54 

ii 

89.799 

799 

0.9090 

62 

41.635 

635 

43 

12 

88.895 

895 

67 

63 

40.610 

610 

32 

13 

87.990 

990 

44 

64 

39.586 

586 

21 
II 

M 
15 

87.086 
86.191 

1.086 
191 

21 

0.8997 

8 

38.561 
37.526 

526 

0.9800 

16 

85.286 

286 

73 

67 

36.492 

492 

0.9790 

17 

84.392      392 

49 

68 

35-457 

457 

80 

18 

83.497 

497 

25 

69 

34423 

423 

70 

19 

82.603 

603 

0.8900 

70 

33.378 

378 

60 

20 

81.708 

708 

75 

7i 

32.333 

333 

50 

21 

80.813 

813 

5° 

72 

31.289 

289 

40 

22 

79.919     9I9 

25 

73 

30.244 

244 

29 

23 

79.014 

2.014 

0.8799 

74 

29.190 

190 

19 

24 

78.119 

119 

73 

75 

28.135 

135 

09 

25 

77.225 

225 

47 

76 

27.080 

080 

0.9698 

26 

76.320    320 

20 

77 

26.016 

016 

88 

27 

75-426 

426 

0.8693 

78 

24-951 

2-951 

77 
66 

28 
29 

74.521 
73.617 

I21 
617 

65 
39 

g 

23.877 
22.822 

877 
822 

55 

30 

72.712 

712 

n 

81 

21.747 

747 

43 

31 

71.797 

797 

0.8583 

82 

20.673 

673 

32 

70.883 

883 

55 

83 

19.598 

598 

18 

33 

69.958 

958 

26 

84 

18.514 

5*4 

05 

34 

69.034 

3-034 

0.8496 

85 

17.419 

419 

0.9592 
79 

if 

68.109 

67.184 

109 

184 

66 
36 

86 

87 

16.324 
15.23° 

324 
230 

65 

37 

66.250 

250 

05 

88 

14.125 

I25 

50 

38 

65.305 

.  305 

0.8373 

89 

13.011 

on 

35 

39 

64.361 

39 

90 

11.876 

1.876 

19 

40    63.406 

406 

06 

91 

10.751 

751 

41 

62.451 

451 

0.8272 

92 

9.617 

617 

0.9487 

42 

61.497 

497 

37 

93 

8.472 

472 

70 

43 

60.532 

S32 

01 

94 

7.3*8 

52 

44 

59.558 

558 

0.8764 

95 

6.153 

r53 

35 

46 

58.593 
57.618 

593 
618 

25 
0.8084 

96 

97 

4.968 
3.764 

0.968 
764 

0-9399 

47 

56.644 

644 

41 

98 

2-539 

539 

81 

48 

55.669 

669 

0-7995 

99 

1.285 

285 

62 

49 

54.685 

685 

46 

IOO 

0.000 

oco 

43 

5° 

53.700 

700 

512 


APPENDIX. 


TABLE  V. — For  comparing  the  different  aerometers  with 
Tralles's  alcoholometer. 

The  statements  of  figures  of  the  other  aerometers  corresponding  to  the  per  cent,  by 
volume  according  to  Tralles's  alcoholometer  stand  in  the  same  horizontal  line. 


,11 

>> 

; 

Veromete 

r  of- 

Jl 

^ 

J 

Aerometer 

of- 

Per  cent,  t 
volume  ace 
ing  to  TK 

Per  cent,  b 
weight. 

Richter. 

1 

Beaume. 

3 

Per  cent,  b 
volume  ac 
ing  to  Tn 

Per  cent,  t 
weight. 

Richter. 

jj 

i 

Beaume. 

•I 

I 

0 

O. 

O.O 

0.0 

10 

ii 

51 

43-47 

12.3 





I 

0.80 

— 

— 

— 

— 

52 

44.42 

— 

12.7 

— 

— 

2 

1.  60 

— 

— 

— 

— 

53 

4536 

— 

13.1 

21 

— 

3 

2.40 

— 

— 

— 

— 

54 

46.32 

— 

13.5 

— 

21 

4 

3-20 

— 

.0 

— 

— 

55 

4729 

41.00 

13.9 

— 

— 

5 

4-IO 

4-00 

.2 

II 

12 

56     - 

48.26 



14.3 

22 

— 

6 

4-8! 

•4 



— 

57 

49-23 

— 

— 

22 

7 

5.62 

— 

.6 

— 

— 

58 

50.21 

— 

15-2 

23 

— 

8 

6-43 

— 

•9 

— 

— 

59 

5I.2O 

— 

15.6 

— 

— 

9 

7-24 

— 

2.1 

— 

— 

60 

52.2O 

45-95 

16.1 

— 

23 

.10 

8.05 

7-50 

2-3 

12 

— 

61 

53.2O 

16.5 

24 

— 

ii 

8.87 

2-5 

— 

— 

62 

54-21 



17.0 

— 

— 

12 

9.69 

— 

2.7 

— 

13 

63 

55-21 

— 

17-5 

25 

24 

'3 

10.51 

— 

2.9 

— 

— 

64 

56.22 

— 

18.0 

— 

— 

M 

u-33 

— 

3-1 





65 

57.24 

51.40 

18.4 

— 

25 

'5 

12.15 

10.58 

3-3 

— 

— 

66 

58.27 

18.9 

26 

— 

16 

12.98 

— 

3-5 

13 

— 

67 

59.32 



19.4 

— 

— 

17 

13.80 

— 

3-6 



68 

60.38 

— 

2O.O 

27 

26 

J  8 

14.63 

— 

3-8 





69 

61.42 

— 

20-5 

— 

— 

19 

15.46 

— 

4.0 



14 

70 

62.50 

57-12 

21.0 

28 

27 

20 

16.28 

13-55 

4-2 



71 

63-58 

21-5 

— 

— 

21 

17.11 

4.4 



— 

72 

64.66 



22.1 

— 

— 

22 

J7-95 

— 

4-6 



— 

73 

65.74 

— 

22.6 

29 

28 

23 

18.78 

— 

4.8 

14 

— 

74 

66.83 

— 

23.2 

— 

— 

24 

19.62 

— 

4-9 

— 

75 

67.93 

62.97 

23.8 

30 

29 

25 

20.46 

1  6.  60 

— 



76 

69.05 

24-4 

— 

— 

26 

21.30 

— 

5-3 



15 

77 

70.18 

— 

25-0 

31 

30 

27 

22.14 

— 

5-5 

— 

78 

71.31 

— 

25-6 

— 

28 

22.96 

— 

5-7 



— 

79 

72.45 

— 

26.2 

32 

— 

29 

23.84 

— 

5-9 

15 

— 

80 

73-59 

69.20 

26.8 

— 

31 

30 

24.69 

19.78 

6.1 

— 

81 

74.74 

— 

27-4 

33 

— 

31 

25-55 

— 

6.4 



— 

82 

75-91 

— 

28.0 

34 

32 

32 

26.41 

— 

6.6 



— 

83 

77.09 

— 

28.7 

— 

— 

33 

27-27 

— 

6.8 

— 

16 

84 

78.29 

— 

294 

35 

33 

34 

28.13 

— 

7.o 

16 

— 

85 

79.50 

75-35 

3O.I 

— 

35 

28.99 

23-56 

7-2 

— 

— 

80 

80.71 

30.8 

36 

34 

36 

29.86 

— 

7-5 

.  . 

— 

87 

81.94 

— 

31-5 

•37 

35 

37 
38 

30.74 
31.62 

25-50 

1:1 

~ 

17 

88 
89 

83.19 
84.46 

— 

32.2 

33-o 

38 

36 

39 

32.50 

— 

8.3 

17 

90 

85-75 

81.86 

33-8 

— 

— 

40 

33-39 

27-95 

8.6 

— 

91 

87.05 

— 

34-7 

39 

37 

_o 

41 

34.28 

8.9 

— 

— 

92 

88.37 

— 

35-5 

40 

38 

42 

35-18 

— 

9.2 

— 

18 

93 

89.71 

— 

36.4 

41 

43 

3608 

.  — 

9.5 

18 

— 

94 

91.07 

— 

37-3 

— 

39 

44 

36.99 

— 

9.8 

— 

— 

95 

92.46 

89-34 

38.2 

42 

40 

g 

37-90 
38.82 

28.30 

IO.2 

19 

19 

96 
97 

93.89 
95-34 

___ 

39-2 
40.3 

43 
44 

41 

47 

39-74 

— 

10.9 

98 

96.84 

— 

41-5 

45 

42 

48 

40.61 

— 

II.  2 

— 

— 

99 

98.39 

— 

42.7 

46 

43 

49 

41-59 

— 

u.6 

— 

— 

100 

100.00 

100.00 

43-9 

47 

— 

50 

42.52 

36.46 

ii.  9 

20 

20 

APPENDIX.  513 

Determination  of  the  True  Strengths  of  Spirit  for  the  Standard 
Temperature  of  59°  F. — Whe,n  for  the  determination  of  the 
strength  of  a  spirit  of  wine,  the  indications  of  the  alcoholo- 
meter and  of  the  thermometer  have  been  read  off,  we  possess 
two  figures  by  means  of  which  the  true  strength  of  spirit  of 
the  spirits  of  wine  to  be  examined,  i.  e.,  the  number  of  liters 
of  absolute  alcohol  contained  in  100  liters  of  the  fluid  to  be 
examined,  when  the  latter  possesses  the  standard  temperature 
of  59°  F.,  is  found  as  follows :  If  the  observed  temperature  of 
the  fluid  is  =  59°  F.,  which  is  indicated  on  the  scale  of  the 
thermometer  with  a  red  mark,  the  figure  read  off  on  the  scale 
of  the  alcoholometer  indicates  at  once  the  "  true  "  strength  of 
spirit.  If,  however,  the  thermometer  shows  a  different  tem- 
perature, in  which  case  the  figure  read  off  on  the  scale  of  the 
alcoholometer  is  termed  the  "  apparent "  strength  of  spirit, 
the  true  strength  of  spirit  is  found  from  the  figure  read  off  on 
the  scale  of  the  alcoholometer  and  the  temperature  with  the 
assistance  of  the  following  table  : 
33 


514 


TABLE  VI. — Determination  of  the  true  strength  of  spirits  for  the 
Standard  temperature  0/59°  F.  (15°  C.). 


Temperature, 
degrees  C. 

Temperature, 
degrees  F. 

3i 

32 

33 

34 

35 

36 

37 

38 

3D 

4^ 

4i 

True  strength  of  spirit  for  the  above  apparent  strengths. 

—25 

—  '3 

47-9 

48.7 

49-5 

50.3 

5LI 

51-9 

52.7 

53-6    54-4 

55-2 

56.0- 

—23-75 

—10.75 

47-4 

48.2 

49.0 

49-8 

50.6 

5L5 

52.3 

53-i 

53.9 

54-7 

55  5 

—22.5 

-8.5 

46.9 

47  7 

48.5 

49.3 

50.1 

51.0 

51.8 

52.6 

53-4 

54-3 

55.i 

—  21.25 

—  6.25 

46.4 

47-2 

48.0 

48.8 

49-6 

50.5 

51-3 

52.1 

53-o 

53-8 

546 

20 

—4 

45-8 

46.7 

47-5 

48.'3 

49-2 

50.0 

50.8 

51-7 

52.5 

53-3 

54-2 

—  18.75 

—  I-7S 

45-3 

46.1 

47-0 

47-8 

48.7 

49-5 

50.3 

Si-2 

52.0 

52-9 

53-7 

—  !7-5 

+0-5 

44-8 

45-6 

46.5 

47.3 

48.2 

49-0 

49.9 

5°-7 

5L6 

52-4 

53  3 

—  16.25 

+2-75 

44-2 

45?i 

46.0 

46.8 

47-7 

.48.5 

49-4 

50.2 

Si.i 

5L9 

52.g 

—  is 

+5 

43-7 

44-6 

45-4 

46.3 

47-2 

48.0 

48.9 

49.8 

50.6 

5i-5 

52-3 

—  '3-75 

+7-25 

43-2 

44.1 

44-9 

45-8 

46.7 

47-5 

48.4 

49-3 

50.1 

51.0 

5i-9 

—12.5 

+9-5 

42.7 

43-5 

44-4 

45-3 

46.2 

47.1 

47-9 

48.8 

49-7 

50.6 

5M 

—11.25 

+  "•75 

42.1 

43-o 

43-9 

44-8 

45.7 

46.6 

47-5 

48.3 

49.2 

50.1 

51.0 

—  10 

+  H 

41.6 

42.5 

43-4 

44.3 

45-2 

46.1 

47.0 

47-9 

48.8 

49-7 

50.6 

-8-75 

+  16.25 

41.  1 

42.0 

42.9 

43-8 

44-7 

45-6 

46.5 

47-4 

48.3 

49-2 

50.1 

—7-5 

+  18.5 

40.6 

4L5 

42.4 

43-3 

44-2 

45.1 

46.0 

46.9 

47-9 

48.8 

49-7 

—6 

+20.75 

40.1 

41.0 

41.9 

42.8 

43-7 

44-6 

45-6 

46.5 

47-4 

48.3 

49.2 

—5 

+  23 

39-5 

40-5 

41.4 

42.3 

43-2 

44-2 

45-1 

46.0 

46.9 

47-8 

48.8 

—3-75 

+25-25 

39-0 

39-9 

40.9 

41.8 

42.7 

43  7 

44.6 

45-5 

46.4 

47-4 

48.3 

-2-5 

+27-5 

38.4 

39-4 

40.3 

4i-3 

42.2 

43-2 

44.1 

45-0 

45.9 

46.9 

47-8 

—1.25 

+29-75 

37-9 

38.9 

39-8 

40.8 

41.7 

42.7 

43-6 

44-5 

45-5 

46.4 

47-S 

0 

+32 

37-4 

38.3 

39-3 

40.3 

41.2 

42.2 

43-i 

44.o 

45-0 

45-9 

46.9 

+  1-25 

+34.25 

36*8 

37-8 

38.8 

39.7 

40.7 

41.7 

42.6 

43-5 

44-5 

45-4 

46.4 

+2.5 

+36.5 

36.3 

37-3 

38.2 

39-2 

40.2 

41.1 

42.1 

43*0 

44.0 

45-° 

45-9 

+3-75 

+38.75 

35-7 

36.7 

37-7 

38.7 

39-7 

40.6 

41.6 

42.5 

43-5 

44-5 

45-4 

+5 

+41 

352 

36.2 

37-2 

38.2 

39-1 

40.1 

41.1 

42.0 

43-0 

44-0 

44-9 

4-6.25 

+43 

34-7 

35  7 

36.7 

37-6 

38.6 

39.6 

40.6 

41.5 

42.5 

43-5 

44-5 

+7-5 

+45-5 

34.1 

35-  * 

36.1 

37-i 

38.1 

39  i 

40.1 

41.0 

42.0 

43-° 

44-0 

+8-75 

+47-75 

33-6 

34-6 

35-6 

36.6 

37.6 

38.6 

39-6 

40.5 

41.5 

42.5 

43-5 

+  10 

+  50 

33-i 

34-1 

35-1 

36.1 

37-1 

38.1 

39-o 

40.0 

41.0 

42.0 

43-°- 

+  11-25 

+52-25 

32-5 

33-6 

34.6 

35-6. 

36.6 

37-5 

38.5 

39-5 

40.5 

41.5 

42.5 

+  I2-5 

+54.5 

32.0 

33-0 

34-0 

35-o 

36.0 

37-0 

38.0 

39-0 

AO.O 

41.0 

42.0 

+  !3-75 

+56-75 

3L5 

32.5 

33-5 

34-5 

35-5 

36-5 

37-5 

38-5 

39-5 

40.5 

4i-5 

-HI 

+59 

31.0 

32.0 

33-o 

34-0 

35-o 

36.0 

37-0 

38.0 

39.0  40.0 

41.0 

+16.25 

+61.25 

3°-5 

31-5 

32.5 

33-5 

34-5 

35-5 

36.5 

37-5 

38-5 

39-5 

40.5 

+17.5 

+63-5 

30.0 

31.0 

32.0 

33.o 

34-o 

35-0 

36.0 

37-0 

38.0 

39-0 

40.0 

+18.75 

+65.75 

29-5 

30.5 

3L5 

32.5 

33-5 

34-5 

35-5 

36-5 

37-5 

38.5 

39-5 

+  20 

+68 

29.0 

30.0 

31.0 

31-9 

32.9 

339 

35-o 

36.0 

37-0 

38.0 

39-o 

+  21.25 

+70.25 

28.5 

29.5 

30.4 

3L4 

32.4 

33-4 

34-4 

35-5 

36.5 

37-5 

38.5 

+  22.5 

+72.5 

38.0 

29.0 

29.9 

30.9 

3i-9 

32.9 

33-9 

34-9 

36.0 

37-o 

38.0 

+  23-75 

+74-75 

27-5 

28.5 

29.4 

30.4 

3L4 

32-4 

33-4 

34-5 

35.5 

36-5 

37  5 

+  25 

+77 

27.0 

28.0 

28.9 

29.9 

30.9 

31.9 

32.9 

33-9 

34-9 

36.0 

37-o 

+  26.25 

+  79.25 

29.5 

27.5 

28.4 

29.4 

3°-4 

3L4 

32.4 

33-4 

34-4 

35-5 

36.5 

+  27-5 

+81-5 

26.0 

27.0 

28.0 

28.9 

29-9 

3°9 

3L9 

32.9 

33-9 

35-o 

36  o 

+  28.75 

+83-75 

25.6 

265 

27.5 

28.4 

29-4 

3°-4 

31-4 

32.4 

33-4 

34-4 

35-5 

+  30 

+  86 

25-1 

26.0 

27.0 

27-9 

28.9 

29.9 

3°-9 

3L9 

32.9 

33-9 

35-o 

+  31.25 

4  88.25 

24.6 

25-5 

26.5 

27.4 

28.4 

294 

30.4 

3i-4 

32-4 

33-4 

34-5 

+  32-5 

+90-5 

24.1 

25.0 

26.0 

26.9 

27.9 

28.9 

29.9 

30-9 

3*-9 

32.9 

34-o 

+33-75 

+92.75 

23.6 

24-5 

25-5 

26.4 

27.4 

28.4 

29.4 

30.4 

3M 

32-4 

33-5 

+35 

+95 

23.1 

24.1 

25.0 

25-9 

26.9 

27.9 

28.9 

29.9 

3°«9 

3J-9 

32.9 

+36.25 

+97-25 

22.7 

23-6 

24-5 

25.4 

26.4 

27.4 

28.4 

29.4 

3°'4 

31-4 

32-4 

+37-5 

+99-5 

22.2 

23.1 

24.0 

24.9 

25.9 

26.9 

27.9 

28.9 

29.9 

30.9 

31-9 

APPENDIX. 

TABLE  VI. — Continued. 


515 


Temperature, 
degrees  C. 

Temperature, 
degrees  F. 

42 

43 

44 

45 

45 

47 

43 

49 

53 

5i 

C2 

True  strength  oi  spirit  for  the  above  apparent  strengths. 

—  25. 

—  13 

56.8 

57-6 

58-4 

59-3 

60.  i 

61.0 

61.8 

62.7 

63.6 

64.5 

65-4 

—23-75 

—  10.75 

56.3 

57-2 

58.0 

58.8 

59-7 

60.6 

61.4 

62.3 

63.2 

641 

65.0 

—22.5 

-8.5 

55-9 

56.7 

57.6 

58.4 

59-3 

60.  i 

61.0 

61.9 

62.8 

63-7 

64.6 

—21.25 

—  6.25 

55-4 

56.3 

57-i 

58.0 

58.8 

59-7 

60.6 

61.5 

62.4 

63-3 

64.2 

—  2O 

—4 

55-o 

55-8 

56-7 

57-6 

58.4 

59-3 

60.2 

61.1 

61.9 

62.9 

63.8 

—  18.75 

—  1-75 

54-6 

55-4 

56.3 

57-1 

58.0 

58.9 

59-7 

60.6 

61.5 

62.5 

63-4 

—  17-S 

4-0.5 

54-i 

55-o 

55-8 

56.7 

57-6 

58.4 

59-3 

60.2 

61.1 

62.1 

63.0 

—  16.25 

+2.25 

53-7 

54-5 

55.4 

56.3 

57-1 

58.0 

58.9 

59-8 

60.7 

61.7 

62.6 

—'5 

+5 

53-2 

54-i 

55.o 

55-8 

56.7 

57.6 

58.5 

59-4 

60.3 

61.2 

62.2 

—  !3-75 

+  7-25 

52.8 

53-6 

54-5 

55-4 

56.3 

57-2 

58.1 

59-o 

59-9 

60.8 

61.8 

—12.5 

+9-5 

52-3 

53-2 

54-1 

55-o 

55-9 

56.8 

57-7 

58.6 

59-5 

60.4 

61.4 

—11.25 

+  "•75 

Sl-9 

52.8 

53-7 

54-5 

55-4 

56.3 

57-2 

58.2 

59-1 

60.0 

61.0 

—  10 

+  H 

5i-4 

52-3 

53  2 

54-i 

55-0 

55-9 

56.8 

57.8 

58.7 

596 

60.6 

-8.75 

+  16.25 

51.0 

51-9 

52.8 

53-7 

54-6 

55-5 

56.4 

57-3 

58.3 

59-2 

60.2 

—7-5 

+  18.5 

50.6 

5i.5 

52-4;  53-3 

54-2 

55.i 

56.0 

56-9 

57-9 

58.8 

59.8, 

-6 

+20.75 

50.1 

51.0 

5i.9   52.9 

53-8 

54-7 

55-6 

56.5 

57-5 

58.4 

59-3 

—5 

+23 

49-7 

5°.6 

5i.5    52.4 

53-3 

54-3 

55-2 

56.1 

57-0 

58.0 

58.9 

—3-75 

+25-25 

49-2 

50.1 

51.1    52.0 

52-9 

53-8 

54-8 

55-7 

56.6 

57.6 

58.5 

—2-5 

+27.5 

48.8 

49.7 

50.61  51.6 

52.5 

53-4 

54-3 

55-3 

56.2 

57-2 

58.1 

—  1.25 

+29-75 

48.3 

49.2 

50.2    51.1 

52.0 

53-o 

53-9 

54-9 

55.8 

5,6.8 

57-7 

0 

+32 

47-8 

48.8 

49-7    50-7 

51.6 

52.5 

53-5 

54-4 

55-4 

'56-3 

57-3 

+  1-25 

+34.25 

47-4 

48.3 

49-3 

50.2 

51-2 

52.1 

53-o 

54.o 

54-9 

!55.9 

;56.9- 

+2.5 

+36.5 

46.9 

47-8 

48.8 

49-8 

50.7 

51.6 

52.6 

53-5 

154.5 

;5-&5 

56.4 

+3-75 

+38.75 

46.4 

47-4 

48-3 

49  3 

50.2 

51-2 

52.1 

53-i 

54-1 

55.0 

56.0 

+5 

+4i 

45-9 

46.9 

47-9 

48.8 

49-8 

50.7 

5L7 

52.7 

53-6 

54.6 

55-6 

+6.25 

+43 

45-4 

46.4 

47-4 

48.3 

49-3 

50.3 

51.2 

52.2 

:53-2 

54.2 

55-i 

+75 

+45-5 

44-9 

45-9 

46.9 

47-9 

48.8 

49-8 

50.8 

51.8 

52-7 

53-7 

54-7 

+8.75 

+47-75 

44-5 

45«4 

46.4 

47-4 

48.4 

49-4 

50.3 

51-3 

52.3 

53-3 

54-2 

+  10 

+  50 

44.0 

44-9 

45-9 

46.9 

47-9 

48.9 

49-9 

50-9 

51.8 

52.8 

53-8 

+  11.25 

+52.25 

43-5 

44-5 

45.5 

46.4 

47-4 

48.4 

49-4 

5°-4 

51-4 

52-4 

53-4 

+  12.5 

+54.5 

43-° 

44.0 

45-0 

46.0 

47-o 

48.0 

48.9 

49-9 

50.9 

51-9 

52-9' 

+  13-75 

+56.75 

42.5 

43-5 

44-5 

45-5 

46.5 

47-5 

48.5 

49.5    5o.5 

5L5 

52-5 

+  15 

+59 

42.0 

43-° 

44.0 

45-o 

46.0 

47-o 

48.0 

49-o 

5o.o 

51.0 

52.0 

+16.25 

+61.25 

41-5 

42.5 

43-5 

44-5 

45-5 

46.4 

47-5 

48.5    49-5 

50-5 

5i.5 

+  175 

+63.5 

41.0 

42.0 

43-o 

44-0 

45-o 

46.0 

47.1 

48.1    49.1 

50.1 

5i.i 

+  18.75 

+65.75 

40.5 

41-5 

42-5 

43.5 

44-5 

45«6 

46.6 

47.6    48.6 

49-6 

50.6 

4-20 

+68 

40.0 

41.0 

42.0 

43-1 

44-1 

45-  i 

46.1 

47-i    48.1 

49-i 

50.2 

+  21.25 

+70.25 

39-5 

40-5 

41.6 

42.6 

43-6 

44-6 

45-6 

46.6 

47-6 

48.7 

49-7 

+  22-5 

+  72.5 

39-o 

40.0 

41.1 

42.1 

43«i 

44.1 

45-i 

46.1 

47-2 

48.2 

40.2-. 

+  23-75 

+  74-75 

38-5 

39-5 

40.6 

41.6 

42.6 

43-6 

44-6 

45-7j46.7 

47*7 

487 

+  25 

+77 

38.0 

39-0 

40.1 

41.  i 

42.1 

43.i 

44-2 

45.2    46.2 

47-2 

48.3 

+  26.25 

+79.25 

37-5 

38.5 

39-6 

40.6 

41.6 

42.6 

43-7 

44-7    45-7 

46.8 

47-8 

+  27.5 

+81.5 

37-o 

38.0 

39-1 

40.1 

41.1 

42.2 

43-2 

44.2    45.2 

46.3 

47-3 

+  28.75 

+83.75 

36-5 

37-5 

38.6 

39-6 

40.6 

41.7 

42.7 

43-7    44-8 

45-8 

46.8 

+  30 

+86 

36.0 

37-o 

38.1 

39-1 

40.1 

41.2 

42.2 

43-2    44-3 

45  3 

46.4 

+  3L25 

+88.25 

35-5 

36.5 

37-6 

38.6 

39-6 

40.7 

41.7 

42.7 

43-8 

44.8 

45-9 

+  32.5 

+90.5 

35-o 

36.0 

37-i 

38.1 

39-i 

40.2 

41.2 

42.3 

43-3 

44.4 

45-4- 

+33-75 

+92.75 

34-5 

35-5 

36.6 

37-6 

38.6 

39-7 

40.7 

41.8 

42.8 

43-9 

44-9 

+35 

+95 

34-o 

35-0 

36.1 

37-1 

38.1 

39-2 

40.2 

41-3 

42.3 

43-4 

44-4 

+36.25 

+97-25 

33-5 

34-5 

35-6 

36.6 

37.6 

38.7 

39-7 

40.8 

,41-8 

42.9 

43-9 

+37-5 

+99.5 

33-o 

34.o 

35-i 

36.1 

37-i 

38.2 

39-2 

40.3 

4L3 

42-4 

43-4 

516 


APPENDIX. 

TABLE  VI. — Continued. 


Temperature, 
degrees  C. 

Temperature, 
degrees  F. 

53 

£4 

55 

56 

57 

53 

59 

60 

61 

62 

63 

True  strengths  of  spirit  for  the  above  apparent  strengths. 

—25 

—  13 

66.3 

67.2 

68.1 

69.1 

70  o 

09 

1.8 

27 

36 

744 

75  3 

—23.75 

—  10.75 

65-9 

66.8 

67.7 

687 

69.6 

°-5 

14 

23 

32 

74.1 

75° 

—22.5 

-8-5 

65-5 

66.4 

67-3 

683 

69  2 

O  I 

I.O 

i  9 

2.8 

73-7 

746 

—21.25 

-6.25 

65.I 

66.0 

67.0 

679 

688 

97 

06 

1  5 

24 

733 

74.2 

20 

—4 

64.7 

65-6 

66.6 

<>7-5 

684 

9  3 

O  2 

i  i 

2.O 

29 

739 

-18-75 

—1-75 

64.3 

652 

66.2 

67.1 

680 

89 

698 

08 

1  7 

2.6 

735 

-^7-5 

+05 

63.9 

64.8 

65.8 

60.7 

67.6 

85 

69  5 

04 

71-3 

2  2 

73i 

16.25 

+  2-75 

63.5 

64-4 

65.4 

66.3 

672 

8.1 

69  i 

70  o 

7o.9 

1.8 

727 

-'5 

+5 

63.1 

640 

65.0 

65-9 

65.8 

67.8 

687 

69.6 

705 

1  4 

724 

—13-75 

+  7-25 

62.7 

63.6 

64.6 

65-5 

664 

67.4 

683 

69  2 

70  2 

71  I 

720 

—125 

+9.5 

62.3 

63.2 

64.2 

651 

660 

67.0 

67-9 

68  9 

69.8 

707 

716 

—11.25 

+  "•75 

61.9 

62.8 

638 

64.7 

657 

656 

67.6 

6S5 

69  4 

7°  3 

71.3 

—  10 

414 

6l.5 

62.4 

63-4 

64  3 

653 

66  2 

67  .2 

68  i 

69  o 

70.0 

70.9 

-8.75 

+  16.25 

OI.I 

62.0 

63.0 

639 

6^9 

65  9 

668 

67  7 

63.7 

69.6 

70S 

—7-5 

+  18.5 

60.7 

61.6 

62.6 

636 

645 

65  5 

664 

67  4 

68.3 

69.2 

70  2 

—  1> 

+  20.75 

60.3 

61.2 

62.2 

63  2 

641 

65  l 

66  o 

670 

67.9 

68.9 

69.8 

—5 

^-23 

59-9 

60.8 

61.8 

628 

637 

647 

656 

666 

67  5 

68.5 

69.4 

-3-75 

+25-25 

59-5 

60.4 

61.4 

624 

633 

643 

65-3 

66  2 

67  2 

68.1 

69.I 

-2.5 

+27-5 

59-1 

Co.o 

61.0 

62.0 

62.9 

639 

64.9 

658 

66.8 

67.7 

68.7 

—1.25 

+29-75 

58.7 

59-6 

60.6 

61.6 

625 

635 

64.5 

654 

66.4 

67-3 

68.3 

0 

+32 

58-3 

592 

CO.  2 

61.2 

62.1 

63.1 

64.1 

650 

66.0 

67.0 

67.9 

41.25 

+3425 

57-8 

588 

59-8 

607 

617 

627 

637 

646 

65.6 

666 

675 

+  2-5 

+3&-S 

57-4 

584 

59-3 

60.3 

61.3 

62.3 

63-3 

64.2 

652 

66.2 

67.1 

+3-75 

+38.75 

57-o 

57-9 

58.9 

599 

60.9 

619 

62.8 

638 

64-8 

65.8 

66.7 

+5 

+41 

56.5 

57-5 

58.5 

59-5 

60.5 

614 

624 

634 

64.4 

65.4 

66  3 

+6.25 

+43 

56.1 

57-1 

58.1 

590 

60.0 

61.0 

620 

630 

640 

64.9 

65  9 

4-7-5 

+45-5 

557 

56.6 

57-6 

586 

596 

60.6 

61  6 

626 

635 

645 

655 

4-8-75 

+47-75 

55-2 

56.2 

57-2 

582 

59.2 

60.2 

61.2 

62  i 

631 

64.1 

65.1 

+  10 

+5° 

548 

55-8 

56.8 

57-8 

587 

59-7 

607 

61.7 

627 

637 

64.7 

4-11.25 

+52-25 

54-3 

55-3 

56-3 

57-3 

583 

59-3 

60  3 

61.3 

62  3 

633 

643 

+  12.5 

+54-5 

53-9 

54-9 

55-9 

56.9 

579 

589 

59-9 

60.9 

61.9 

62.9 

63-9 

+  13-75 

+56.75 

53-5 

54-4 

55-4 

56-4 

574 

584 

59-4 

60  \ 

61.4 

62  4 

634 

+*S 

+59 

53-o 

54.0 

55-° 

560 

57-° 

580 

590 

600 

6  i.o 

62.0 

63.0 

4-16.25 

+61.25 

5^-5 

53-5 

54-6 

55-6 

56.6 

576 

586 

59-6 

60.6 

61.6 

62.6 

+17-5 

+63-5 

52.1 

53-1 

54-i 

55-1 

56.1 

57-i 

58.1 

59i 

60.  i 

61.1 

62.1 

+  18-75 

+65.75 

51.6 

52.6 

53-7 

547 

557 

56.7 

577 

58.7 

59-7 

60.7 

61.7 

4-20 

+68 

51-2 

52.2 

53-2 

542 

SS2 

562 

57  2 

583 

59  3 

60.: 

61.3 

+21.25 

+70-25 

50-7 

5'-7 

52.7 

538 

548 

55.8 

568 

57-8 

58.8 

59-8 

60.8 

+22.5 

+725 

50.2 

5*-3 

52-3 

533 

54-3 

553 

56-3 

57-4 

58.4 

59-4 

60.5 

+23.75 

+74-75 

49-8 

50.8 

51.8 

528 

539 

549 

559 

569 

57-9 

58-9 

60.0 

+25 

+77 

49-3 

5°-3 

51.4 

524 

534 

544 

55  5 

565 

57-5 

58,5 

59-5 

+26.25 

+79.25 

48.8 

49-9 

5°-9 

5»-9 

530 

540 

55° 

56.0 

57-o 

58.1 

59-1 

o    /• 

+27-5 

-i-81-5 

48.4 

49-4 

50.4 

5l-S 

525 

535 

545 

55-6 

56  6 

57-6 

58.6 

+28.75 

+83-75 

47-9 

48.9 

50.0 

51.0 

520 

53 

54i 

55 

56i 

5l'2 

582 

+30 

+86 

47-4 

48.4 

49-5 

5°  5 

51-6 

526 

536 

547 

557 

56.7 

57-7 

+3'-25 

'+88.25 

46.9 

48.0 

49.0 

50.1 

5r-i 

521 

532 

542 

552 

56.2 

57-3 

+32-5 

490.5 

46.4 

47-5 

48-5 

49.6 

506 

5'-7 

527 

537 

54-8 

55-8 

56.8 

+33-75 

+92.75 

46.0 

47.0 

48.1 

49  i 

50.2 

51-2 

522 

53 

543 

55  3 

564 

+35 

+95 

45-5 

46.5 

47-6 

48.6 

497 

5°7 

51.8 

52. 

538 

54-9 

55-9 

+36-25 

+97  25 

45.0 

46.0 

47.1 

48.2 

49- 

5°-3 

5i-3 

524 

534 

54-4 

55-4 

+  375 

+995 

44-5 

45-6 

46.6 

47-7 

48.7 

49.8 

50.8 

51       529 

539 

55-° 

APPENDIX. 


517 


TABLE  VI. — Continued. 


Temperature, 
degrees  C. 

Temperature, 
degrees  F. 

I                ! 

64      65 

66 

67 

68      69 

70 

71      72 

73 

74 

True  strength  of  spirit  for  the  above  apparent  strengths. 

—25 

—13 

76.2 

77-1 

78.0 

79.0   79.9   80.8   81.7 

82.6 

83.5 

84.4 

85-3 

—23.75 

—  10-75 

75  9 

76.8 

77.7 

78.6;  79.5   80.4   81.3 

82.2 

83.2 

84.1 

—22.5 

-8.5 

75.5 

75.4 

77-3 

78.2;  79.1 

80.  i 

81.0 

81.9 

82.8 

83.7 

84^6 

—21.25 

-6.25 

75-1 

76.0 

77-o 

77.9  !  78.8  79.7 

80.6 

81.6 

82.5 

83-4 

84.3 

—  20 

—4 

74-8  j  75-7 

76.6 

77.5^  78.4  70-3 

80.3 

81.2 

82.1 

83.0 

84.0 

-18.75 

-i-75 

74-4  I  75-3 

76.2 

77.2    78.1 

79-0 

79.9 

80.9 

81.8 

82.7 

83.6 

-17.5      +0.5 

74-0 

74.9 

75-9 

76.8    77-7 

78.6 

79.6 

80.5 

81.4 

82.4 

83-3 

—16.25'  +2.75 

73-7    74-6 

75-4 

76.4    77-4  '  78.3 

79.2 

80.2 

81.1 

82.0 

82.9 

-15         +5 

73-3    74.2 

75-1 

76.1    77-0 

77-9 

78.9 

79-8 

80.7 

81.7 

82.6 

—13-75 

+  7-25 

72.9    73-9 

74-8 

75-7    76.7 

77.6    78.5 

79-5 

80.4 

8i.3J82.3 

—12.5      +9-5 

72.6 

73.5 

744 

75-4    76.3 

77.2    78.2 

79.1 

80.  i 

81.0,81.9 

—11.25  +11-75 

72.2    73-1 

74.1 

75-0   75.9 

76.9 

77.8 

78.8 

79-7 

83.7  81.6 

—10      1  +  14 

71.8   72.8 

73-7 

74-6 

75-6 

76.5 

77-5 

78.4 

79-4 

80.3  81.3 

—8.75+16.25 

7L5    72-4 

73.4    74-3 

75-2 

76.2    77.1 

78.1 

79-0 

80.0  80.9 

-7-5    +18.5 

71.1 

72.1 

73.o 

73-9 

74.9    75.8    76.8 

77-7 

78.7 

79.6180.6 

-6 

+  20.75 

70.7 

7L7 

72.6 

73.6 

74-5   75-5 

76.4 

77-4 

78.4 

79-3  80,3 

—5 

+  23 

70.4 

71-3 

72.3 

73-2 

74.2 

75-1 

76.1 

77-0 

78.0 

79.0:79.9 

—3-75  +25.25 
-2.5  i  +  27-5 

70.0 
69.6 

71.0 
70.6 

71.9 
71-5 

72.9 
72.5 

73-8 
73.5 

74-8 
74-4 

75.7 
75-4 

76.7 
76-3 

77-7 
77-3 

78.6  79-6 
78.3  1  79-2 

—1.25  +29.75 

69-3 

70.2 

71.2 

72.1 

73-1 

74.0  i  75.0 

76.0 

77.0 

77-9 

78.9 

o       +32 

68.9 

69.8 

70.8 

7L8 

72.7    73-7 

74-7 

75-6 

76.7 

77-6 

78.5 

+  1.25 

+  34-25 

68.5 

69.5 

70.4 

71-4 

72.3 

73-3 

74-3 

75-3 

76.2 

77-2 

78.2 

+2.5 

436.5 

68.1 

69.1 

70.0 

7i.o 

72.0 

72.9 

73-9 

74-9 

75-9 

76.8 

77-8 

67.7 

68.7 

69.6 

70.6 

71.6 

72.6    73.5 

74-5 

75-5 

76.5 

77-4 

+5' 

+41 

67-3 

68.3 

69-9 

70.2 

71.2 

72.2 

73-1 

74-1 

75-1 

76.1 

77.1 

+6.25 

+43 

66.9 

67.9 

69-3 

69.8 

70.8 

71.8 

72.8 

73-7 

74-7 

75-7 

76.7 

+7.5 

+  45-5 

66.5 

67.5 

68.5 

69-4 

704    71.4 

72.4 

73-4 

74-3 

75-3 

76.1 

+8.75 

+47-75 

66.1 

67.1 

68.1 

69.0 

70.0   71.0 

72.0 

73-0 

74-0 

74-9  75-9 

+  10 

+  50 

65.7 

66.7 

67.6 

68.6 

69.6    70.6 

71.6 

72.6    73.6 

74-6  75.5 

+  11.25 

+  52.25 

65.3   66.3 

67.2 

68.2 

69.2    70.2 

71.2 

72.2 

73-2 

74-2  75.2 

4-12.5 

+54-5 

648(65.8 

66.8 

67.8 

68.8   69.8 

70.8 

71.8 

72.8 

73-8  74.8 

+  13-75 

+  56.75 

64-4  !  65.4 

66.4 

67.4 

68.4 

69.4 

70.4 

71.4 

72.4 

73-4  74-4 

+  15       +59 

64.0  65.0 

66.0 

67.0 

68.0 

69.0    70.0 

71.0 

72.0 

73-0  74.o 

+  16.25  +61.25 

63.6  64.6 

65.6 

66.6 

67.6 

68.6   69.6 

70.6 

71.6 

72.6 

73.6 

+  17.5  1+63.5 

63.2  64.2 

65-2 

66.2   67.2 

68.2   69.2 

70.2 

71.2 

72.2 

73.2 

+  i8.75'+65-75 

62.7   63.7 

64.7 

65.8   66.8 

67.8   68.8 

69.8 

70.8 

71.8,72.8 

+20       +68 

62.3   63.3 

64.3 

65.3 

66.3 

67.4   68.4 

69.4 

70.4 

7L4  72.4 

+  21.25+70.25 

61.9   62.9 

63.9 

64.9 

65.9 

66.9   68.0 

69.0   70.0 

;  71.0172.0 

+  P2.5    +72.5 

61.4   62.4 

63-5 

64.5   65.6 

66.5    67.5 

68  6 

09.6 

70.6 

7[-6 

+23.75+74.75 

61.0   62.0 

63.0 

64-1    65.1 

66.1 

67..i 

68'.  i 

69.2 

7O  2 

71.2 

+  25 

+  77 

60.5    61.6 

62.6 

63.6   64.6 

65.7 

66.7 

67-7!  68.7 

69.8 

70.8 

+26.25  +79.25 

60.  i    61.1 

62.1 

63.2   64.2 

65.2 

66.3 

67-3  i  68.3 

69.4 

70.4 

+27.5  1+81.5 

59.6   60.7 

61.7 

62.7   63.8 

64.8 

65-8 

66.9  {  67.9 

68  9 

T" 

+28.75  483.75 

59.2   60.2 

61.3 

62.3    63.3   64.4 

65-4 

66.4  !  67.5 

68.5 

6^5 

+30 

+86 

58.7:59.8 

60.8 

61.9   62.9   63.9 

65.0 

66.0   07.1 

68.1 

69.  T 

+31  25  +88.25 

58.3    59-3 

60.4 

61.4   62.5 

63.5 

64.5 

65.6   66.6 

67.7  68.7 

+32  5  1+90.5 

57-8    58.9 

59.9   61.0   62.0 

63.1 

64.1 

65.1    66.2 

67  2  1  68  -> 

+33-75  +92.75 

57-4    58.4 

59.5    60.5    61.6 

62.6 

63.7 

64.7  !  65.8 

66!8l67lo 

+35 

495 

56  9  '  58.0 

59.0   60.  i    61.1 

62.2 

63-2 

64-3   65.3 

66.4  167.4 

+36.25 

+97-25 

56.5  '  57-5 

58.6    59.6    60.7 

61.7 

62.8 

63.8164.3 

65-9  67.0 

+  37-5 

+  99-5     56.0 

57-1 

58.1    59.2,60.2 

61.3   62.3 

63-4  1  64.4 

65.5  66.5 

-518 


APPENDIX. 

TABLE  VI . —  Concluded. 


1 

Temperature., 
degrees  C. 

1 

Temperature, 
degrees  F. 

75 

76 

77 

78     79 

1        1 

i             1 

80     81 

1         1 

82      83 

84     85 

86 

True  strength  of  spirit  for  the  above  apparent  strengths. 

i 

i 

i 

| 

—25 

—  13 

862 

87.1 

88.0 

88.9  89.7  90.6  91.1 

;92-3  93-1 

93-9  94.7195.5 

—23.75 

-10.75 

85*9 

86.8 

87.7 

88.5189.4  90.3  91.4  92.0  92.8 

93-6  94-4 

95-3 

-22.5 

-8.5 

85.5 

86.4 

87.3 

88.2  89.1 

90.0  90.  £ 

5  91.7  02.5 

93-3  94-2 

|95.° 

—  21.25 

—6.25 

85.2 

86.1 

87.0 

87.9  88.8  89.6  90.5  91.4  92.2 

93-0  93-9 

94-7 

20 

—4 

84-9 

85.8 

86.7 

87.6,88.5 

89.3   00,2  9X.I    91.9 

92.8  93.6!  94.  4 

—  l8.75 

—  1.75 

84.5 

85-4 

86.3 

87.2l88.i 

89.0  89.9  90.8  91.6 

92.5  93-3 

94-1 

—  17.5 

+0.5 

84.2 

85.1 

86.0 

86.9  87.8  88.7  89.6  90.4  9i.3 

92.2  93.0 

—  16.25 

+  2.75 

83-9 

84.8 

85.7 

86.6  87.5 

88.4  89.3  90.1  91.0 

9i.9!92.7 

93.'6 

-15 

+5 

83.5 

84-4 

85-4 

86.3187.2 

88.1  88.9  89.8  90.7 

91.6:92.4 

93-3 

—13-75 

+7-25 

83.2 

84.1 

85.0 

85.9186.8 

87.7  88.6  89.5  90.4 

91.3  92.1 

93.° 

—12.5 

+  9-5 

82.9 

83.8 

84-7 

85.6  86.5 

87.4  88.3  89.2  90.1 

91.0  91.9 

92.7 

—  11.25 

+  11-75 

82.5 

83.5 

84-4 

85.3  86.2 

87.1  88.0  88.9  89.8 

90.7  91.6 

92.5 

—  10 

-8.75 

+  14 
+  16.25 

82.2,83.1 
81.9  82.8 

84.1 
83.7 

85.0  1  85.9 

86.8  87.7  88.6  89.5 
86.5  87.4  88.3  89.2 

90.4    91.3  j  92.  2 
90.1   91.0  91.9 

-7-5 

+  18.5 

81.5 

82.5 

83-4 

84*385^ 

86.2  87.1 

88.0  88.9 

83.8  90.7  9I-6 

—6 

+  20.75 

81.2 

82.1 

83.1 

84.0  '85.0 

85.9  86.£ 

>  87.7  88.6 

89.5  90.5 

91.4 

—5 

+  23 

80.9 

81.9 

82.8 

83.7  84.6  85.6  86.5  87.4  88.3 

89.2  90.2 

91.1 

—3-75 

+25.25 

80.5 

81.5 

82.4 

83.4  84.3 

85.2  86.2  87.1  88.0 

88.9  89.9 

90.8 

—2.5 

+  27-5 

80.2 

81.1 

82.1 

83.0  8l.o 

84.9  85.9  86.8  87.7 

88.6  80.6 

90.5 

—  1.25 

-29.75 

79-8 

80.8 

81.8 

82.7,83.7 

84.6  85.5  86.5  87.4  88.3  89.3 

90.2 

o 

+32 

79-5 

80.4 

81.4 

82.4  '83.3 

i     i 

84.3  85.2  86.2  87.1 

88.0  89.0 

89.9 

| 

j 

+  1.25 

+34-25 

79-1 

80.  i  jSi.i 

82.0  83.0 

83.9  !  84.  9  85.8  86.8 

87.7:88.6 

89.6 

+2.5 

+36.5 

78.8 

79-7  i 

80.7 

81.7:82.6 

83.6  84.5  85.5  86.4 

87.4  88.3 

89.3 

+3.75 

+  38.75 

78.4 

79.4 

80.3 

81.3  82.3 

83.2  84.2  85.2  86  i 

87.1  88.0 

+  5 

+41 

78.0 

79  -O 

80.0 

81.0  81.9 

82.9  83.9  84.8  85.8 

86.7  87.7 

88  6 

+6.25 

+  43 

77.7 

78.  6  j 

79-6 

80.6  81.6 

82.5  83.5  84.5  85.4 

86.4  87.4 

88.*3 

4  7-5 

+  45-5 

77-3 

78-3| 

79-3 

80.2  Si.  2 

82.2  83.2  84.1:8=5.1 

86.1  87.0 

88.0 

+8.75 

+47-75 

76.9 

77-9 

78.9 

79.9  80.8 

8r.8  82.8 

83.8  84.8 

85.7  86.7 

87.7 

+  10 

+50 

76.5 

77-5 

78-5 

79-5  80.5 

81.5  82.4 

83-4  84.4 

85.4  86.4 

87.3 

+  11.25 

+  52.25 

76.2 

77.1 

78.1 

79.1  80.  i 

81.1  82.1 

83.1184.1 

85.0  86.0 

87.0 

+12.5 

+54-5 

75.8! 

76.8 

77-8 

78.8  79-7 

80.7  81.7 

82.7,83.7 

84.7.85.7 

86.7 

+13.75 

75-4 

76.4 

77-4 

78.4  79-4 

80.4  81.4 

82.4183.4 

84-3  85.3 

86.3 

+  15 

+59' 

75-0 

76.0 

77-0 

78.0  79.0 

80.0  81.0 

82.0  ''  83.0 

84.0  85.0 

86.0 

+  16.25 

+  61.25 

74-6  1 

75.6 

76.6 

77-6  78-6 

1  79.  6  80.6 

8i.6!82.6 

83.6  84.6 

85-6 

+  17-5 

+63-5 

74-2 

75-2 

76.2 

77.2  78.2 

79.2  80.3 

8r.3!82.3: 

83-3  84.3 

85.3 

+  18.7^ 

+65.75 

73-8 

74-8 

75-8 

76-8  77-9 

78.7J79-9 

80.9  81.9 

82.9  83.9 

84.9 

+  20 

+68 

73-4 

74-4  75-1 

76.5:77.5 

78.5(79.5  80.5  81.5 

82.6  83.6 

84.6 

+21.25 

+70.25 

73-0 

74.0  74-7 

76.  i  |  77.  i 

78.1  79.i 

80.  i  81.2 

82.2  83.2 

84.2 

+  22.5 

+  72.5 

72.6 

73-6  74.4 

77.7,78.7 

79.8  80.8 

81.8  82.9 

83.9 

+  23-75 

+  74-75 

72.2 

73-2  74-3 

75.3  ;!  76.  3 

77.3178.4 

79.4  80.4 

81.5  82.5 

83.5 

+25 

+  77 

71.8 

72.8  73.9 

74-9  75-9 

76.9178.0 

79.0  80.0 

81.1  82.1 

83-2 

+26.25 

+  79-25 

71.4 

72.4  73-5 

74-5  75-5 

76.5  77-6 

78.6  79-6 

80.7  81.7 

82.8 

+27-5 

+  81.5 

71.0 

72  o  73-0 

74-1  75.i 

76.1  77.2  78.2  79.3 

80.3  81.4 

8;.!.4 

+28.75 

483.75 

70.6 

71.6  72.6 

73-7  74.7 

75.7!  76.8 

77-8  78.9 

79.9  81.0 

82.0 

+30 

+  86 

70.2 

71.2  72.2, 

73-3  74.3 

75.3I76.4 

77-4  78.5 

79.5  80.6 

81.7 

+31.25 

+  88.25 

69.7 

70.8  71.8 

72.9  73-9 

74.  9  !  76.0  77.0  78.1 

79.1  80.2 

81.3 

+32.5 

+90.5 

69-3 

70.4  71.4 

72.4  73-5 

74-5  175-6 

76.6  77.7  78.7  79.8  80.9 

+  33-75 

+  92.75 

68.9  69.9  71.0! 

72.0  73.1 

74-  1  i  75  -2 

76.2  77-3 

78.3  79.4  80.5 

+  35 

+95 

68.5  69.5  70.6: 

71.6  72.7 

73-7  74-8 

75.8  76.9 

77.9  79.0  80.  i 

+36.25 

+  97-25 

68.1, 

&9.l|70.I 

71.2  72.2 

73-3  74-3 

75-4  76.5 

77-5  78.6  79-7 

+37-5 

+99-5 

67.6, 

58.7,69.7 

70.8  71.8 

72,9  73.9 

75.0  76.1   77.1  78.2  79.3 

i                      i 

i 

i         ' 

APPENDIX. 


519 


Table  VI.  has  two  entries  :  one  in  the  uppermost  horizontal 
line  for  the  observed  statements  of  the  alcoholmeter,  hence 
the  apparent  strengths  from  31  to  44  per  cent. ;  the  other  in 
the  first  vertical  column  for  the  statements  of  Fahrenheit's 
thermometer  from  — 13°  to  +99.5°.  On  the  place  where  a 
vertical  and  horizontal  column  cross,  the  strength  correspond- 
ing to  the  normal  temperature  of  59°  F.,  i.  e.  the  true  strength 
of  spirits,  is  found. 

If,  for  instance,  the  alcoholometer  immersed  into  a  sample 
of  spirits  of  wine  indicates  an  apparent  strength  of  77  per  cent, 
and  the  thermometer  the  temperature  of  the  fluid  as  25.5°  F., 
the  figure  77  has  to  be  found  in  the  uppermost  horizontal  col- 
umn, and  then  the  vertical  column  belonging  to  it  is  followed 
downward  until  the  horizontal  line  is  reached  in  which  stands 
the  figure  25.5  in  the  column  containing  the  degrees  of  tem- 
perature. Here  the  statement  82.4  will  be  found  as  the  true 
strength  of  spirit,  and  this  figure  indicates  that  at  the  normal 
temperature  of  59°  F,  100  liters  of  the  spirit  of  wine  exam- 
ined contain  82.4  liters  of  absolute  alcohol. 

When  the  apparent  strength  read  off  on  the  alcoholometer 
consists  of  a  whole  number  and  a  fraction,  the  true  strength 
-corresponding  to  the  whole  number  is  determined  in  the  above 
manner,  and  the  surplus  fraction  added  to  the  number  found. 

If,  for  instance,  the  temperature  read  off  is  74.75°,  and  the 
apparent  strength  81}  per  cent.,  the  true  strength  belonging 
to  81  per  cent,  and  74.75°,  which  is  — 78.4,  is  first  found  in 
the  table,  and  to  this  is  added  the  fraction  £  =  0.72,  or  suffi- 
ciently accurate  =  0.7.  This  gives  78.4-1-0.7  =  79.1  per  cent, 
as  the  nearest  accurate  true  strength. 


520 


APPENDIX. 


TABLE  VII. — Determination  of  the  true  volume  of  alcoholic  fluids 
from  the  apparent  volume  at  different  temperatures. 

(According  to  A.  F.  W.  Brix. ) 


cJ 

I 
! 

Degrees  F. 

55-57 

58-60 

61-64 

65-69 

70-74 

75-79 

80-84 

85-89 

90-94 

Reducing  factors  for  the  above  strengths  of  spirits  of  wine. 

—  10 

+  I4 

I.OI98 

1.0203 

1.0207 

1.0213 

I.O22O 

1.0227 

1.0233 

1.023811.0246 

—8-75 

+  16.25 

0189 

0193 

0197 

0203 

O2IO 

0217 

0222 

0227;  0235 

—7-5 

+  I8-5 

Ol8o 

0183 

0187 

0193 

O2OO 

0206 

02  1  I 

02161  0223 

—6 

+20.75 

0170 

0173 

0177 

0183 

0189 

oi9> 

0200 

0205 

02  1  1 

—  5 

+  23 

0161 

0164 

0168 

0173 

0179 

0185 

0190 

0194 

O2OO 

—3-75 

+  25-25 

0152 

oi55 

0158 

0163 

0169 

0175 

0179 

0183 

Ol89 

—2.5 

+27-5 

oi43 

0146 

0148 

oi53 

0159 

0164 

0168 

0172 

0178 

—1.25 

+  29-75 

oi33 

0136 

0138 

0143 

0148 

oi53 

0157 

0161 

0166 

—  o 

+  32 

0123 

0126 

0128 

0132 

0138 

0142 

0X46 

0150 

0154 

+  1-25 

+34.25 

0114 

0117 

0118 

0122 

0127 

0131 

0135 

0139 

0142 

+2.5 

+  36.5 

0105 

0107 

0108 

0112 

OIl6 

0120 

0124 

0128 

0130 

4-3-75 

+38.75 

0095 

0097 

0098 

0102 

0105 

0109 

0113 

0116 

0118 

+5 

+  41 

0085 

0087 

0088 

0091 

0094 

0098 

OIOI 

0104 

0106 

-1-6.25 

+43-25 

0075 

0077 

0078 

0080 

0083 

0086 

0089 

OOQ2 

0094 

+  7-5 

+45-5 

0066 

0067 

0068 

0070 

OO72 

0075 

0078 

0080 

0082 

+8.75 

+47-75 

0056 

0057 

0058 

0060 

OO6I 

0064 

0066 

0068 

0070 

+  10 

+50 

0046 

0047 

0048 

0050 

OO5O 

0053 

0054 

0056 

0058 

+  11.25 

+  52-25 

0036 

0037 

0038 

0039 

0039 

OO4I 

0042 

0044 

0045 

+  125 

+545 

0026 

0027 

0027 

0028 

0028 

OO29 

0030 

0031 

0032- 

+  '3-75 

+56.75 

0015 

0916 

0016 

OOI7 

OOI7 

OOI7 

0018 

0019 

0019 

+  15 

+  59 

1.0005 

1.0005 

1.0005 

1.0005 

i  oco6 

I.  OOO6  I.  OOO6 

1.  0006 

i  0006 

+  16.25 

4-61.25 

0.9995 

09995 

°9995 

°-9995 

o  9994 

0.9994:0.9994 

0.99940.9993 

+  17-5 

+63.5 

9985 

9985 

9984 

9984 

9983 

9983   9982 

9982!  9981 

+  18.75 

+65-75 

9975 

997  S 

9974 

9973 

9972 

9971   9970 

9969!  9968 

+  20 

+68 

9965 

9965 

9963 

9962 

9961 

9960   9958 

9957  9955 

+  21.25 

+  70.25 

9955 

9955 

9952 

995  i 

9950 

9949  9946 

994SJ  9942 

+  22.5 

+  72-5 

9945 

9944 

9941 

9940 

9939 

9937)  9934 

9932 

9929 

+  23-75 

+74-75 

9934 

9933 

993° 

9929 

9927 

9925 

9922 

9919 

9916 

+  25 

+77 

9923 

9922 

9919 

9917 

9915 

9912 

9909 

9906 

9Q03 

+  26.25 

+  79-25 

9912 

99" 

9908 

9906 

9903 

9901  9897 

9893 

9890 

+  275 

+81.5 

990i 

9900 

9897 

9894 

9891 

9889'  9885 

9880  9877 

+  28.75 

+83.75 

9890 

9889 

9886!  9882 

9879 

9876  9872 

9867  j  9864 

+  30 

+  86 

9879 

9877 

9874)  9870 

9866 

9883!  9859 

9854!  9851 

+  3I-25 

+88.25 

o  9868 

0.9865 

0.9862  0.9858 

o  98540.98500.9846 

0.98410.9837 

Explanation  of  Table  VII. 

Alcohol,  or  alcohol  and  water,  heated  above  or  cooled  below 
the  standard  temperature,  expands  or  contracts.  Now,  for  in- 
stance, what  is  the  volume  of  10,000  liters  of  a  mixture  of  82 
per  cent,  by  volume  at  +  5°  C.  (41°  F.)  at  the  standard  tern- 


APPENDIX.  521 

perature.*  In  the  horizontal  column  below  80-84  and  in  the 
vertical  column  at  +  5°  C.  (41°  F.)  is  the  reducing  factor 
1.0101;  hence  10,000  liters  are  10,000  X  1.0101  =  10,101 
liters.  82  being  exactly  the  mean  of  80-84,  the  reduction  is- 
accurate.  At  83°  the  factor  would  have  to  be  increased  by  J- ; 
at  84  by  f,  and  consequently  the  factor  for  83°  would  be  1.0101 
+  (1.0104  —  1.0101)  |  =  1.01016.  For  the  practice  the  above 
factors  suffice  without  change.  The  measuring  of  the  temper- 
ature and  reading-off  of  the  percentage  of  the  spirit  should  b& 
done  in  the  storage-cellar,  and  not  in  a  warmer  room,  for 
instance,  the  office,  as  is  frequently  the  custom  to  the  disad- 
vantage of  the  seller. 

*  This  table  is  calculated  for  a  standard  temperature- of  15.5P-C.  (60aF.), 


522 


APPENDIX. 


> 

:l 

«<4 

* 

:s 

•i. 


I 

^ 

i  ? 

!i 


^   'H 

1  ^ 
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1 

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9 

t* 


I  1 


t^»  ON  HH 


rn 


rj-  r>.  N  q  q  f^ 

6    TJ-ON'^-C\ri-sLr>w 
M'-'OOaN  ONOO  OO  00 


vr>  M 

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fOt^-i-Hvo  >-"^o  c4 
Mi-ii-iOO    ON  O 


ONOO  OO   t^  t^. 


1-1   ^J  Q   ^°°.   °^rt'~'   rot^f?1-1   rj-XJ   ro  I-   O  .N   "3-oq 

' 


o\  ONOO  oo  oo  r--  r^v 


r-O'< 
HH    O    O 


ONON  O\OO  OO 


(     o 
t-^O 


ON  ONOO  00  OO 


1-1  q\  N  q  PO  q  N  t^«  vr>vq  q  t^\q  t^« 

N    W    TJ-vO  00*i-<'    TJ-t^wu^O    rfO\4-c5^-«I~-.fn  ON^O 
ONOO    t^vO   vrjiorj-^nrOM    W   1-1   O    O   O    ON  ONOO  00   t^  r^ 


t»  o\  M  TJ-  i>» 
r^\O  vOLOT*- 


ON  ONOO  OO  00 


N    ^7-00    Tj->O   1-1   ti    ^-  1-1    «    TJ-  ON  t^«OO   O   v>  "-"    ON  ON  HH    rh 

C^O'NO"  N  •^•t^.d  roi>.«  Lri^'f^Lodvd  «  i>.TJ-d 

ONOO  OO   1>.O   vr>vOTJ-fOrnNi-ii-iOOOON  ONOO  00  OO 


,        ^OMD   ON 
v£)iOTffO 


»-i  rooo  vq  oo  N  ONOO  q>  fn  qsvq  >oo  oq 

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ONOO  *-•  t^vo  iOTt-TfrnroN«i-ioOOON  ONOO  00 


o     qoo  rj  q  <?•-; 


O°v  O  O  N 

O    O    ONOO 


t--.^  q\oo  oq 
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«    HH    Q    O    ON  ON  ONOO 


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ON  ON 


O   10  O   •<*•  O   10  i-    J-  ro  ON 

rONi-ii-iwOOON  ONOO 


>d  vd  t^od  d  p5 

HH    O    ONOO  OO   t^- 


<o  TJ-  q\  q  lo^q  «  q  PJ  oq  t^  q\  to  q  ON  >-< 
d  d  d  pJ  PO  ^od  w 

N    1-1    O    ONOO   t>»vO  vO 


APPENDIX. 


523 


TABLE  IX. — For  the  reduction  of  specific  gravities  to 
saccharometer  per  cent. 

(According  to  Balling.) — Temperature  63.5°  F. 


JJ 

o  v 

c 
A*" 

fl 

c 

rt"" 
^  g 

C 
05  "" 

ll 

!« 

c 

O  V 

«  S 

*  S 

, 

rt  fl 

«  S 

8  E 

S  S 

4) 

>>     v 

•  1) 

.-s 

M  « 

.- 

cfS 

•r 

c*2 

'JT 

bf>« 

'>   .si 

.- 

si 

S 

•3  " 

CS 

'-a  *" 

i 

t""  "" 

s 

•5  °1  • 

£   *3  -  <••' 

<a 

•3  '.  ^ 

M 

u 

tC 

ill 

M 

1C 

If  « 

1 

Jj"fl' 
J- 

B 

HI 

M 

o 

||  § 

o 

IS  8 

'£ 

Ms, 

'i 

sis. 

'S 

1  i  ij 

'o 

G  1  fr 

'S 

E  1  si 

'S 

^  °  S. 

ft 

0  t,  p. 

a 

s  *«  ** 

O,    i 

0  v.  a. 

& 

a. 

o  •-  p- 

a 

C/3     U 

Cfl 

u 

en 

U 

CJ 

ca 

U 

in 

o 

1.  0000 

0.000 

1  .0040 

1.  000 

1.0080 

2.COO 

I.OI2O 

3.000 

i.  0160 

4.000 

1.0200 

5.000 

i.  ooo  i  i  0.025 

41 

025 

81 

025 

121 

025 

16; 

025 

201 

025 

2!  050 

42 

050 

82 

050 

122 

050 

162 

050 

2O  2 

050 

3   °75 

43 

075 

83 

°75 

123 

°75 

163 

075 

2O3 

075 

4 

IOO 

44 

IOO 

84 

IOO 

124 

IOO 

164 

IOO 

204 

IOO 

5 

125 

45 

125 

85 

125 

125 

125 

125 

205  j    125 

6   150 

46 

150 

86 

I5° 

126 

15° 

1  66 

150 

206 

150 

7 

175 

47J   175 

87 

175 

127 

175 

167 

'75 

207 

175 

8    200 

48    200 

88 

200 

128 

2CO 

i  68   200 

208 

2OO 

9   225 

49 

225 

89 

225 

129 

225 

169   225 

209 

225 

i.ooio;   250 

1.0050 

250 

i  .0090 

250 

I.OI3O 

250 

1.0170   256 

I.02IO    250 

ii1   275 

51 

275 

91 

275 

131 

275 

171 

275 

211 

275 

12    300 

52 

300 

92 

300 

I32 

300 

172 

300 

212    300 

13 

325 

53 

325 

93 

325 

133    325 

I73J   325 

213,   325 

I4 

35° 

54 

35° 

94 

350 

134   35° 

174   35° 

214   35° 

375 

55 

375 

95 

375 

135   375 

175   375 

215 

375 

1  6 

400 

56 

400 

96 

400 

136:  400 

i  76   400 

216 

400 

17 

425 

57 

425 

97   425 

137 

425 

177 

425 

217 

425 

18 

450 

58 

45° 

98 

45° 

138 

45° 

178 

45° 

218 

45° 

19 

475 

59 

475 

99 

475 

139 

475 

179 

475 

219   475 

i  .0020 

500 

i.  0060 

500 

1.  0100 

500 

1.0140 

500 

1.0180 

500 

I.022C 

500 

21 

525 

61 

525 

IOI 

525 

141 

525 

181 

52 

221 

525 

22 

55° 

62 

55C 

IO2 

55° 

142 

55° 

182   550 

222    550 

23 

575 

63 

575 

103 

575 

M3 

575 

183   57 

223   575 

24 

600 

64 

600 

104 

600 

144 

600 

184!   600 

224   600 

25 
26 

625 
650 

65 
66 

625 

650 

105 
106 

625 

650 

»45 

146 

625 

650 

185!   62 
186   65 

225!   625 
226   650 

27 

675 

67 

675 

107 

675 

147 

675 

187   67 

227:   675 

28 

700 

68 

700 

1  08 

700 

148 

700 

1  88   70 

228  r   700 

29 

725 

69 

725 

109 

725 

149 

725 

189   72 

229'   725 

I.OO3O    750 

1.0070 

75° 

I.OIIO 

750 

1.0150 

75° 

1.0190 

75 

1.0230   750 

31   775 

7f 

775 

III 

775 

151 

775 

191   77 

231!   775 

32   800 

72 

800 

112 

800 

'52 

800 

1921   80 

232   800 

331  82^ 

73 

825 

"3 

825 

153 

825 

193   82 

233   825 

34 

850 

74 

850 

114 

8^0 

154 

850 

194   85 

2341   850 

35 

875 

75 

875 

"5 

875 

875 

195   87 

235   875 

36 

900 

76)   900 

116 

900 

ip 

900 

196   90 

236   900 

37 

925 

77 

925 

117 

925 

157 

925 

197   92 

237   925 

38 

95° 

78 

95° 

118 

95° 

i5s 

95° 

198   95 

238,   95° 

39 

975 

79 

975 

119 

975 

159 

975 

199   97 

239   975 

524 


APPENDIX. 

TABLE  IX. —  Continued. 


i 

ifl« 

j  £S« 

o  iJ  *< 

i{2  J 

oij~ 

<j  v  ~ 

>, 

*"  w!  u 

>i    |   "  «  0 

>, 

M"  " 

>, 

"wo 

£ 

bio"" 

>, 

V  S  V 

I 

o 

lit 

'i  i-isS. 
*  111-! 

> 

o 

IP 

*> 

£ 

bfi 
o 

IP 

ri 

So 

if! 

be 

0 

Is! 
§|.s 

o.  c  — 

tfl 

1 

ill 

1  'SI8 

1 

tj  5 

1C 

O. 

811 

o  <->  5 

1 

III 

CJ 

£  ,u 

<ft" 

U 

to 

U 

Cfl 

U 

en 

U 

1  .0240 

6.000 

1.0290  7.219 

1.0340 

8.438 

1.0390 

9.657 

1.0440 

10.857 

1.0490 

12.047 

241 

024 

291   244 

341 

463 

39' 

68  1 

441 

881 

491 

07I 

242 

048 

292   268 

342 

488 

392 

706 

442 

9  CM 

492 

°95 

243 

°73 

293;   292 

343 

512 

393 

73' 

443 

928 

4-3 

119 

244 

097 

2941   3*6 

344 

536 

394 

756 

444 

952 

494 

142 

245 

122 

295  i   34' 

345 

560 

395 

780 

445 

976 

495 

1  66 

246 

I46 

296   36^ 

346 

584 

396 

804 

446 

II.OOO 

496 

190 

247 

170 

297!   389 

347 

609 

397 

828 

447 

023 

497 

214 

248 

'95 

298,   4U 

348 

633 

398 

853 

448 

047 

238 

249 

219 

299   438 

349 

657 

399 

877 

449 

081 

499 

261 

1.0250 

244 

1.0300   46^ 

r.o35o 

681 

i  .0400 

90, 

1.04:0 

°95 

i  .0500 

285 

251 

268 

301!   488 

35i 

706 

401 

925 

451 

119 

50i 

3°9 

252 

292 

302   512 

352 

731 

402 

950 

452 

142 

502 

333 

253 

3i6 

303   536 

353 

7^6 

4°3 

973 

453 

1  66 

5°3 

357 

254 

34i 

304   560 

354 

780 

404 

IO.CCO 

454 

ICO 

5°4 

381 

25  < 

365 

305   584 

355 

804 

405 

023 

455 

213 

505 

404 

256 

389 

306   609 

356 

828 

406 

047 

45  6 

238 

506 

428 

257 

413 

307'   633 

357 

853 

407 

071 

457 

261 

5°7 

452 

258 

438 

308   667 

358 

877 

408 

095 

458 

285 

508 

476 

259 

463 

309'   681 

359 

901 

409 

119 

459 

309 

509 

5co 

1.0260 

488 

1.0310'   706 

1.0360 

925 

1.0410 

142 

1.0460 

333 

1.0510 

523 

261 

512 

311!   731 

361 

95° 

411 

1  66 

461 

3^9 

511 

547 

262 

536 

312   756 

362 

975 

412 

1  90 

462 

512 

57i 

263 

56o 

313   78o 

363 

9.000 

4'3 

214 

463 

404 

595 

264 

584 

314   804 

364 

024 

414 

238 

464 

428 

514 

619 

265 

609 

315!   828 

365 

048 

415 

261 

465 

452 

5'5 

642 

266 

633 

3i6!   85' 

366 

°73 

416 

285 

466 

476 

666 

267 

657 

317   877 

367 

097 

4'7 

309 

467 

500 

5'7 

690 

268 

681 

318,   901 

368 

122 

418 

333 

468 

523 

5i8 

7H 

269 

706 

319   925 

369 

I46 

419 

357 

469 

547 

738 

1.0270 

73i 

1.0320   95° 

1.0370 

170 

1.0420 

38' 

1.047° 

57* 

1.0520 

761 

271 

756 

32i|   975 

195 

421 

404 

47i 

5<55 

521 

785 

272 

780 

322  8.0CO 

372 

219 

422 

428 

472 

619 

522 

809 

273 

804 

323   024 

373 

244 

423 

452 

473 

642 

523 

833 

274 

828 

324'   048 

374 

268 

424 

476 

474 

676 

524 

857 

275 

853 

325'  073 

375 

292 

425 

500 

475 

690 

525 

88r 

276 

877 

326   097 

376 

3l6 

426 

523 

476 

714 

526 

904 

277 

901 

327    122 

377 

341 

427 

547 

477 

738 

527 

928 

278 

925 

328    146 

378 

365 

428 

571 

478 

761 

528 

952 

279 

950 

329    17° 

379 

389 

429 

595 

479 

785 

529 

976- 

1.0280 

975 

1.0330    195 

i  .0380 

4'3 

1.0430 

619 

i  .0480 

809 

1.0530 

13.000 

281 

7.000 

331,   219 

38. 

438 

43  1 

642 

481 

833 

023 

282 

024 

332,   244 

382 

463 

432 

666 

482 

857 

532 

047 

283 

048 

333   268 

383 

48S 

433 

690 

483 

881 

533 

071 

284 

°73 

334   292 

384 

512 

434 

484 

504 

534 

095, 

285 

097 

335   3'6 

385 

536 

435 

738 

485 

928 

535 

119 

286 

122 

336   34i 

386 

560 

436 

761 

486 

952 

536 

142 

287 
288 

I46 
170 

337,   365 
338   389 

387 
388 

584 
609 

438 

•785 
809 

487 
488 

976 

I2.COO 

537 
538 

1  66 

289 

«9S 

339'   413 

389 

633 

439 

833 

489 

023 

539 

214 

APPENDIX. 


525 


TABLE  IX.— Concluded. 


i  _  B 

,  c 

a 

,  c 

c 

•  .S 

!  j=  ~ 

A 

43  •£ 

"5  c 

Is 

i'- 

•  y  § 

0  V 

8S 

o  £ 

to 

1  "  £ 

>, 

S| 

>, 

!J 

g, 

If 

£ 

w>~ 

£ 

Sjj 

a 

'  c  2 
1  ^3  ^ 

a 

I* 

1 

|s 

§ 

fl 

rt 

•l« 

rt 

IL 

SB 

||| 

M 

0 

ill 

a 

1  «  8 

||  g 

0 

II  § 

°  £  § 

i 

CO 

U 

1 

CO 

u 

1 

Els 
38' 

'o 

JSS. 

'o 

£ 

CJ 

°0 

a. 

CO 

J22L 

1.0540 

13-238 

1.0577 

14.119 

10614 

15.000 

1.0651 

15.860 

1.0688 

16.721 

1.0730 

17.681 

541 
542 

261 

285 

578 

579 

142 

1  66 

'  615 
616 

024 
046 

652 
653 

883 
907 

689 
1.0690 

744 
767 

732 

734 

725 

772 

543 

309 

1.0580 

190 

617 

o7o 

654 

930 

691 

790 

736 

818 

544 

333 

581 

214 

618 

093 

655 

953 

692 

814 

738 

863 

545 

357 

582 

238 

619 

iie 

656 

976 

693 

837 

1.0740 

909 

546 

381 

583 

261 

1.0620 

139 

657 

16.000 

694 

860 

742 

954 

547 

404 

584 

285 

621 

162 

658 

023 

695 

883 

744 

18.000 

548 

428 

585 

309 

622 

1  86 

659 

046 

696 

907 

746 

045 

549 

452 

586 

333 

623 

209 

1.  0660 

070 

697 

93° 

748 

090 

1-0550 

476 

587 

357 

624 

232 

66  1 

093 

698 

953 

1.0750 

500 

588 

38i 

625 

255 

662 

116 

699 

976 

752 

181 

552 

523 

589 

404 

626 

278 

663 

139 

1.0700 

1  7.000 

754 

227 

553 

547 

1.0590 

428 

627 

302 

664 

162 

7OI 

022 

756 

272 

554 

571 

591 

452 

628 

325 

665 

1  86 

702 

045 

758 

3*8 

555 

595 

592 

476 

629 

348 

666 

209 

703 

067 

1.0760 

363 

556 

619 

593 

500 

1.0630 

371 

667 

232 

7°4 

090 

762 

409 

557 

642 

594 

523 

631 

395 

668 

255 

7°5 

764 

454 

558 

666 

595 

547 

632 

418 

669 

278 

706 

136 

766 

5  c° 

559 

690 

596 

571 

633 

44i 

1.0670 

302 

707 

158 

768 

545 

1.0560 

7*4 

597 

595 

634 

464 

671 

325 

708 

181 

1.0770 

590 

561 

736 

598 

6i(, 

635 

488 

672 

348 

709 

204 

772 

636 

562 
563 

761 
785 

599 
1.0600 

665 

636 
637 

5" 

534 

673 
674 

371 
395 

1.0710 
711 

227 
250 

774 
776 

68  1 
727 

564 

,  809 

601 

690 

638 

557 

675 

418 

712 

272 

778 

772 

565 

833 

602 

7M 

639 

58, 

676 

441 

295 

1.0780 

818 

566 

857 

603 

738 

1.0640 

604 

677 

464 

7'4 

3'8 

782 

863 

567 

881 

604 

761 

641 

627 

678 

480 

7*5 

340 

784 

909 

568 

904 

605 

785 

642 

650 

679 

511 

716 

363 

786 

954 

569 

928 

606 

643 

674 

i.  0680 

534 

717 

386 

788 

19.000 

1.0570 

952 

607 

833 

644 

697 

68  1 

557 

718 

409 

1.0790 

045 

976 

608 

857 

645 

721 

682 

581 

719 

43' 

792 

090 

572 

14.000 

609 

88  1 

646 

744 

682 

604 

1.0720 

454 

794 

136 

573 

023 

1.0610 

904 

647 

767 

684 

627 

722 

500 

796 

181 

574 

047 

611 

928 

648 

790 

685 

650 

724 

545 

798 

227 

575 

071 

612 

952 

649 

814 

686 

674 

726 

590 

1.0800 

19.272 

576 

095 

6,3| 

976 

1.0650 

837 

687 

697 

728 

636 

526 


APPENDIX. 


TABLE  X. —  Comparative  synopsis  of  the  aerometers  for 
must  generally  used. 


i 

V 

. 

il 

§ 

Sugar,  i 

>er  cent. 

c 

M 

ft 

§ 

Sugar,  p 

er  cent. 

f 

6| 

i|-§ 

by  w 

°ight. 

^ 

S.lb'S 

by  w< 

:ight. 

£ 

«-•«;= 

£  *^ 

I 

s! 

ifN 

1 

S.^ 

K^^- 

1 

i.^ 

%£^ 

. 

& 

O! 

Babo. 

Pillitz. 

Q 

10 

w 

Babo. 

Pillitz. 

o 

I.05I 

12.5 

10.5 

8.2 

7 

1.091 

21.8 

I8.3 

17-5 

_ 

52 

12.8 

10.7 

8.5 

92 

22.1 

18.5 

I7.8 

— 

53 

13.0 

10.9 

8-7 

— 

93 

22.3 

1  8.6 

1  8.0 

— 

54 

13.2 

II.  I 

8.9 

— 

94 

22.5 

1  8.8 

18.2 

— 

55 

'3-5 

"•3 

9.1 

— 

95 

22.7 

18.9 

18.4 

— 

56 

'3-7 

9-4 

— 

96 

22.9 

19.0 

18.6 

— 

57 

14.0 

11.7 

9-7 

— 

97 

23.1 

19.2 

18.8 

— 

58 

14.2 

12.0 

9-9 

8 

98 

23-3 

19-3 

19.0 

— 

59 

14.4 

12.2 

IO.I 

— 

99 

23-5 

19-5 

19.2 

13 

60 

14.7 

12.4 

10.4 

— 

l.IOO 

23-7 

19.7 

19.4 

61 

14.9 

12.6 

10.6 

— 

01 

23-9 

19.9 

19.6 

— 

62 

12.8 

10.8 

— 

02 

24.2 

20.1 

19.9 

— 

63 

15.4 

13.0 

ii.  i 

— 

°3 

24.4 

20.3 

20.  i 

— 

64 

i5.6 

13-3 

"•3 

— 

04 

24.6 

2O.5 

20.3 

— 

65 
66 

,5.8 

16.1 

'3-5 
'3-7 

11.5 
11.8 

9 

°5 
06 

24.8 
25.0 

2O.8 
21.0 

20.5 

20.7 

67 

16.3 

13.9 

12.0 

— 

07 

25.2 

21.2 

20.9 

14 

68 

16.5 

14.1 

12.2 

— 

c8 

254 

21.4 

21.  1 

— 

69 

1  6.8 

M-3 

I2-5 

— 

09 

25-7 

21.6 

21.4 

— 

70 

17.0 

12.7 

— 

10 

25-9 

21.8 

21.6 

— 

17.2 

4.1 

I2.9 

— 

ii 

26.1 

22.0 

21.8 

— 

72 

14.8 

13-2 

— 

12 

26.3 

22.2 

22.O 

— 

73 

17.7 

15.0 

— 

13 

26.5 

22.4 

22.2 

— 

24 

17.9 

1C.  2 

13*6 

10 

14 

26.7 

22.6 

22.4, 

— 

]l 

18.1 
18.4 

15-4 
I5.6 

13-8 
I4.I 

I 

26.9 
27.1 

22.8 
23.0 

22.6 
22.8 

15 

77 

18.6 

15-8 

14.3 

— 

17 

27.4 

23.2 

23.I 

78 

1  8.8 

15-9 

M.5 

— 

18 

27.6 

23-5 

23.3 

— 

79 

IO.O 

16.1 

'4-7 

— 

19 

27.8 

23.8 

23-5 

— 

80 

J9«3 

16.3 

15.0 

— 

20 

28.0 

24.1 

23-7 

— 

81 

!9-5 

16.5 

If.  2 

— 

21 

28.2 

24-3 

23-9 

— 

82 

19.7 

16.7 

15-4 

ii 

22 

28.4 

24.6 

24.1 

— 

83 

20.  o 

16.9 

— 

23 

28.6 

24.9 

24-3 

— 

84 

20.2 

17.1 

IS-9 

— 

24 

28.9 

25-2 

24.6 

— 

85 

2c.4 

17-3 

16.1 

— 

25 

29.1 

255 

24.8 

16 

86 

20.7 

17.4 

16.4 

— 

26 

29-3 

— 

25.0 

— 

87 

20.9 

17.6 

16.6 

— 

27 

29-5 

— 

25.2 

— 

88 

21.  1 

17.8 

16.8 

— 

28 

29.7 

— 

254 

— 

89 

21.4 

1  8.0 

17.1 

— 

29 

29.9 

— 

25.6 

— 

90 

21.6 

18.2 

17-3 

12 

3° 

3O.I 

25.8 

APPENDIX. 


527 


TABLE  XI. —  Table  to  Oechsle's  aerometer  for  must. 


gravity. 

u."S 

^  ***  o 

°-«S 

a»l 

gravity. 

^  £ 

ll* 

gravity. 

8| 

rt  g 
O  ~fj  Ji 

all 

gravity. 

83 

41 

111 

I 

III 

Percentc 
crystall 
grape-s 

1 

CO 

Ps 

M£  * 

C3  ~  « 

o 

! 

Degrees 
Oechsle 
meter  f< 

Percenta 
crystall 
grape-s 

1 

11  pi 

1041 

41 

8.0 

1059 

59 

13.0 

1076 

76 

17.2 

1093 

93 

21.7 

1042 

42 

8-3 

1060 

60 

13.2 

1077 

77 

I7'5 

1094 

94 

21.9 

1043 

43 

8.6 

1061 

61 

13.4 

1078 

78 

17.8 

1095 

95 

22.2 

1044 

44 

8.9 

1062 

62 

13-6 

1079 

79 

18.0 

1096 

96 

22.5 

1045 

45 

9.2 

1063 

63 

13-9 

io£o 

80 

18.3 

1097 

97 

22.7 

1046 

46 

9.4 

1064 

64 

14.0 

1081 

81 

18.5 

1098 

98 

23.0 

1047 

47 

9-7 

1065 

65 

14.2 

1082 

82 

18.8 

1099 

99 

23.2 

1048 

48 

9.9 

1066 

66 

14.4 

1083 

83 

19  i 

IIOO 

100 

23.4 

1049 

49 

10.2 

1067 

67 

14-7 

1084 

84 

19.4 

IIOI 

101 

23.7 

1050 
1051 

5° 
51 

10-5 

10.8 

1068 
1069 

68 
69 

15.0 

1085 
1086 

85 
86 

19.7 
20.  o 

I1O2 
IIO3 

IO2 
I03 

23.9 
24.2 

1052 

52 

II.  I 

1070 

70 

15.5 

1087 

87 

20.2 

IIO4 

IO4 

24.5 

1053 

53 

ii.  4 

1071 

I5.8 

1088 

88 

20.4 

IIO5 

'05 

24.8 

1054 

54 

11.7 

1072 

72 

16.1 

1089 

89 

2O.7 

nob 

106 

25.0 

i°55 

55 

ii  9 

1073 

73 

16.3 

1090 

90 

20.9 

1107 

107 

25.2 

1056 

56 

12.2 

1074 

74 

16.5 

1091 

21.2 

IIOS 

1  08 

25.4 

I057 

57 

12.5 

1075 

75 

16.9 

1092 

92 

21.4 

1109 

109 

25.7 

1058 

58 

12.7 

TABLE  XII. — To  Massonfours  aerometer. 


Degrees, 
according  to 
Massonfour. 

Weight  of  a 
liter, 
grammes. 

Degrees, 
according  to 
Massonfour. 

Weight  of  a 
liter, 
grammes. 

Degrees, 
according  to 
Massonfour. 

Weight  of  a 
liter, 
grammes. 

I 

1008 

8 

1059 

15 

1116 

2 

1015 

9 

1067 

16 

"25 

3 

IO22 

10 

1075 

17 

"34 

4 

IO29 

ii 

1083 

18 

"43 

5 

1036 

12 

109! 

r9 

1152 

6 

1043 

13 

1099 

20 

1161 

7 

1051 

H 

IIO; 

' 

TABLE  XIII. — For  comparing  per  cent,  of  sugar  with  per  cent, 
of  extract  and  the  specific  gravity.     By  Pillitz. 


C  'N* 

jj8-J 

IB 

C/) 

Extract, 
per  cent. 
(Balling). 

Specific 
gravity. 

Sugar, 
per  cent 
(Pillitz). 

«"5o 
«§:§ 

IS5! 

,3  SB 

o  rf< 
(fi.tj 

11 

s-l 

MfcpLH 
£°<~ 

Extract, 
per  cent. 
(Balling). 

Specific 
gravity. 

O 

4-3 

.0172 

9 

13-3 

.0543 

18 

22.3 

.0930. 

I 

5-3 

.O2I2 

10 

14.3 

.05»S 

19 

23.3 

.0975 

2 

6.3 

.0253 

ii 

15-3 

.0627 

20 

24-3 

.  1017 

3 

7-3 

.0294 

12 

16.3 

.0670 

21 

25.3 

.  IO6O 

4 

8.3 

•0335 

13 

17-3 

.0713 

22 

26.3 

.  IIO3 

5 

9-3 

.0376 

H 

18.3 

.0757 

23 

27-3 

.  1146 

6 

10.3 

.0417 

15 

19-3 

.0800 

24 

28.3 

.1189 

7 

ii.  3 

•0459 

16 

20.3 

.0844 

25 

29.3 

.  I232 

8 

12.3 

.0501 

17 

21.3 

.0887 

-528 


APPENDIX. 


TABLE  XIV. — For  determining  the  content  of  per  cent,  of  acetic 

acid  contained  in  a  vinegar  of  —  specific  gravity. 

Temperature  15°  C.  ( 59°  F. ) . 

(According  to  A.  C.  Oudemans.) 


Anhydrous 
•acetic  acid, 

Specific  gravity. 

Anhydrous 
acetic  acid, 

Specific  gravity. 

Anhydrous 
acetic  acid, 

Specific  gravity 

per  cent. 

per  cent. 

per  cent. 

100 

1-0553 

66 

1.0717 

32 

1.0436 

99 

1.0580 

65 

1.0712 

31 

1.0424 

98 

1  .0604 

64 

1.0707 

30 

I.O4I2 

97 

1.0625 

63 

1.0702 

29 

1  .0400 

96 

1.0644 

62 

1.0697 

28 

1.0388 

•95 

1.  0660 

61 

1.0691 

27 

1.0375 

94 

1.0674 

60 

1.0685 

26 

1.0363 

93 

1.0686 

59 

1.0679 

25                      1.0350 

92 

1.0696 

58 

1.0673 

24                      L0337 

9i 

1.0705 

57 

1.0666 

23 

1.0324 

90 

1.0713 

56 

1  .0660 

22 

I.03II 

-89 

1.0720 

55 

1-0653 

21 

1.0298 

88 

1.0726 

54 

1.0646 

20 

1.0284 

«7 

1.0731 

53 

1.0638 

19 

1.0270 

86 

1.0736 

52 

1.0631 

18 

1.0256 

85 

1.0739 

51 

1.0623 

17 

1.0242 

84 

1,0742 

5° 

1.0615 

16 

1.0228 

83 

1.0744 

49 

1.0607 

15 

I.O2I4 

82 

1.0746 

48 

1.0598 

14 

1.0200 

8  1 

1.0747 

47 

1.0589 

13 

I.OI85 

So 

1.0748 

46 

1.0580 

12 

I.OI7I 

79 

1.0748 

45 

1.0571 

II 

I.OI57 

78 

1.0748 

44 

1.0562 

10 

1.0142 

77 

1.0748 

43 

1.0552 

9 

I.OI27 

76 

1.0747 

42 

1.0543 

8 

I.OII3 

75 

1.0746 

4i 

1-0533 

7 

1.0098 

74 

1.0744 

40 

I-0523 

6 

1.0083 

73 

1.0742 

39 

L05I3 

5 

1.0067 

72 

1.0740 

38 

1.0502 

4 

1.0052 

7i 

1.0737 

37 

1,0492 

3 

1.0037 

70 

1.0733 

36 

1.0481 

2 

1  .0022 

69 

1.0729 

35 

1  .0470 

I 

I.OOO7 

68 

1.0725 

34 

1.0459 

O 

0.9992 

67 

1.0721 

33 

1.0447 

APPENDIX. 


529 


TABLE  XV. — For  determining  the  content  of  per  cent,  of  acetic 
acid  contained  in  a  vinegar  of —  specific  gravity. 

(According  to  Mohr.) 


Anhydrous 
acetic  acid. 

Specific  gravity. 

Anhydrous 
acetic  acid, 

Specific  gravity. 

Anhydrous 
acetic  acid, 

Specific  gravity. 

per  cent. 

per  cent. 

per  cent. 

100 

1.0635 

66 

1  .0690 

33 

1.0440 

99 

1-0655 

65 

1.  0680 

32 

1  .0420 

98 

1.0670 

64 

1.  0680 

31 

I.04IO 

97 

1  .0680 

63 

1.  0680 

30 

1.0400 

96 

1  .0690 

62 

1.0670 

29 

1.0390 

95 

1.0700 

61 

1  .0670 

28 

1.0380 

94 

1.0706 

60 

1.0670 

*1 

1.0360 

93 

1.0708 

59 

1.  0660 

26 

1.035° 

92 

1.0716 

58 

1.  0660 

25 

1.0340 

9i 

1.0721 

57 

1.0650 

24 

1.0330 

1.0730 

56 

1  .0640 

23 

1.0320 

1.0730 

55 

1  .0640 

22 

I.03IO 

1.0730 

54 

1.0630 

21 

I.O29O 

87 

1.0730 

53 

1.0630 

2O                        I.O27O 

86 

1.0730 

52 

I.C620 

19                        1.0260 

85 

1.0730 

51 

1.0610 

18 

1.0250 

84 

1.0730 

5° 

i.  0600 

17 

1  .0240 

83 

1.0730 

49 

1.0590 

16 

1.0230 

82 

1.0730 

48 

1.0580 

'5 

I.O22O 

81 

1.0732 

47 

1.0560 

H 

1.0200 

80 

'•°735 

46 

1.0550 

13 

1.0180 

79 

I-°735 

45 

1.0550 

12 

1.0170 

78 

T-°733 

44 

1.0540 

II 

1.0160 

77 

1.0732 

43 

1.0530 

10 

1.0150 

76 

1.0730 

42 

1.0520 

9 

1.0130 

75 

1.0720 

4i 

1.0510 

8 

I.OI20  ' 

74 

1.0720 

40 

1.0510 

7 

I.OIOO 

73 

1.0720 

39 

1.0500 

6 

1.0080 

72 

1.0710 

38 

i  .0490 

5 

1.0070 

7i 

1.0710 

37 

1.0480 

4 

1.0050 

70 

i  .0700 

36 

1.0470 

3 

1  .0040 

79 

1.0700 

35 

1.0460 

2 

I.CO2O 

68 

1.0700 

34 

1.0450 

I 

I.COIO 

67 

i  .0690 

34 


530 


APPENDIX. 


TABLE  XVI. — Comparison  of  the  scales  of  Reaumur  s,  Celsius 's, 
and  Fahrenheit' s  thermometers. 


Reaumur. 

Celsius. 

Fahrenheit. 

Reaumur. 

Celsius.           Fahrenheit. 

—  ls 

-18.75 

_ 

33 

41.25                   106.25 

14 

17-50 

0.50 

34                 42.50                  108.50 

13 

16.25 

2-75 

35                 43-75                 1*0.75 

12                        15.00 

5.00 

36                 45.0°                 113.00 

ii                 !3  75 

7.25 

37                46.25                 115.25 

10                 12.50 

9.  co 

38                47.50                117.50 

9 

11.25 

11-75 

39                 48.75                 H9.75 

8 

10.00 

14.00 

40                50.00 

I  22.00 

7 

8.75 

16.25 

4i                 51.25 

124.25 

6 

7.50 

18.50 

42                52.5° 

126.50 

5 

6.25 

20.75 

43                53-75 

I28.75 

4 

5.00 

23.00 

44                  55-00 

131.00 

3 

3-75 

25-25 

45                 56.25 

133.25 

2 

2.50 

27.50 

46                 57-5° 

I35.50 

I 

1.25 

29*75 

47                  58.75 

137-75 

0 

o 

32.00 

48                 60.00 

I4O.OO 

+  1 

+  1-25 

34.25 

49                  61.25 

142.25 

2 

2.50 

36-50 

5° 

62.  so 

144.50 

3 

3-75 

38.75 

5i 

63.75 

146.75 

4                  5-°° 

41.00 

52 

65.00 

149.00 

5                  6.25 

43.25 

53 

66.25 

ICI.25 

6                  7.50 

45-50 

54 

67.5° 

153.50 

7                  8.75 

47-75 

55 

68.75 

155-75 

8                 10.00 

50.00 

56 

70.00 

It;8.OO 

9                 11-25 

52.25 

57 

7!-25 

160.25 

10                 12.50 

54-5° 

58 

72.50 

162.50 

ii 

13.75 

56-75 

59 

73-75 

164.75 

12 

15.00 

59.00 

60 

75.00 

167.00 

13                        16.25 

61.25 

61 

76.25 

169.25 

H                        17-5° 

63.50 

62 

77-5° 

171.50 

15                        18-75 

6575 

63 

78.75 

173.75 

1  6                        2O.CO 

68.00 

64 

80.00 

176.00 

17            21.25 

70.25 

65 

81.25 

178.25 

1  8                 22.50 

72.50 

66 

82.50 

180.50 

J9                 23.7^; 

74-75 

67 

83.75 

182.75 

20 

25.00 

77.00 

68 

85.00 

185.00 

21 

26.25 

79.25 

69                  86.25 

187.25 

22 

27.50 

81.50 

70                 87.50 

189.50 

23 

28.75 

83.75 

7i                  88.75 

I9L75 

24 

30.00 

86.00 

72                 90.00 

194.00 

11 

31-25 
32.50 

8825 
90.50 

73                 9L25 
74                 92.50 

196.25 
198.50 

27 

33-75 

92.75- 

75                 93-75 

200.75 

28 

35-°o 

95.00 

76                 95-0° 

203.00 

29 

36.25 

97.25 

77                 96-25                 205.25 

30 

37-5° 

99.50 

78                 97-5° 

207.50 

31 

38.75 

101.75 

79                 98.75 

209.75 

32 

40.00 

104.00 

80 

IOO.OO 

2I2.OO 

INDEX. 


ACETAL,  25-27 
Acetaldehyde,  24,  25,  249 
Acetates  and  their  preparation,  313-348 
Acetic  acid,  248 

bacteria,  1 
composition  of,  SO 
determination  of,  by  titration, 

222-224 

of  the  chemical  constitu- 
tion of,  3 
of  content  of,  in  vinegar, 

113,  528,  529 

formation  of,  by  chemical  pro- 
cesses, 9,  10 
of,  from  alcohol,  6 
glacial,  3 
newly  formed,  disturbances  due 

to  the  quantity  of,  12<)-131 
occurrence  of,  9 
oxygen  required  for  formation 

of,  31 

practical  yield  of,   from  alco- 
hol, 109 

processes  of  preparation  of,  255 
production    of,   from    its    ele- 
ments, 6 
pure,  27-29 

production    of,    from    wood 

vinegar,  296-313 
theoretical  yield  of,  from  alco- 
hol, 108 
yields  of,  29-32 
yields  of,  34,  35,  112,  113 
aldehyde,  24,  25 

;     anhydride  in   vinegar,   determina- 
tion of,  220-224 
degeneration  of  wine,  189,  190 
ether,  preparation  of,  184,  185 
fermentation,  products  of,  23-35 
Acetification,  accelerated,  97-99 

of  shavings,  quantity  of  vinegar  re- 
quired for,  96 
Acetoraeter,  220 
Acetometry,  220-224 
Acetone,  243,  244 
oils,  355 

plant  for  production  of,  353,  354 
preparation  of,  352-355 

(531) 


Acetone,  properties  of,  248,  249 
Acid,  testing  must  for,  387-390 
Acids  in  fruits,  371,  372 

detection  of,  in  vinegar,  227-229 
Aerometers,    different,    comparison    of, 
with  Tralles'  alcoholometer,  512 
for  must,  comparative  synopsis  of, 

526 

After-wine,  190-192 
Air,  absorption  of  moisture  by,  467 
Albucases.  discovery  by,  2 
Albuminous  substances  in  fruit,  372 
Alcohol,  absolute,  376 

and  water,  actual  content  in  mix- 
tures of,  and  contraction 
in  mixing,  511 
mixtures  of,  114.  115 
specific    gravity   of    mix- 
tures of,  509 
calculation    for    the   reduction   of, 

with  water,  109,  110 
composition  of,  30 
content  of,  in  spirits  of  wine,  112 
determination  of,  214-220 

of  chemical  constitution  of,  3 
formation  of  acetic  acid  from,  6 
practical  yield  of  acetic  acid  from, 

109,  112,  113 
theoretical    yield    of    acetic    acid 

from,  108 
Alcoholic  fermentation,  8,  9 

liquid,  addition  of  finished  vinegar 

to,  108 

addition  of  phosphate  to,  129 
constitution     of     fundamental 
materials  used  in  the  prepar- 
ation of,  113-116 
contraction  of.  117 
definition  of,  104 
determination  of  true  volume 
of,   from   apparent   volume, 
520 

distribution  of,  in  the  gener- 
ator, 46-52 
examples   of    composition   of, 

110 

gradual  increase  of  alcohol  in, 
106. 107 


532 


INDEX. 


Alcoholic  liquid,  strengthening  of,  118, 

119 

heating  apparatus  for,  95,  96 
low  wine  for,  111 
preparation  of,  104-116 
proportion   between  per  cent, 
by  weight  and  by  volume  of, 
510 
quantity  of,  to  be  worked  in  a 

generator,  117,  118 
receipts  for,  110,  111 
role  of  vinegar  in,  105 
Alcoholometer,  determination  of  alcohol 

by,  214,  215 

Aldehyde,  7,  24,  25,  249 
Alden  evaporator,  improved,  470-472 

manner  of  operating,  474- 

476 

patent    for    evaporating    fruit,  465 
Ale,  sour  vinegar  from,  168,  169 
Alkalies,  effect  of,  on  wood,  236,  237 
Alkaloid  in  wine,  377,  378 
Allyl  alcohol,  244 
Aluminium  acetate,  320-323 
hydrate,  320 

sulphate,  decomposition  of,  321 ,  322 
Ammonia  test  solution,  222 
Ammonium  acetate,  316,  317 
Amyl  alcohol,  115 
Amyloid,  235,  236 
Anchovy  vinegar.  182 
Anise  vinegar,  181 

Anthon's  table  for    finding  content    of 
anhydrous  sugar  in  saturated  solu- 
tions of  glucose   392 
Antimony,  use  of,  for  determining  tem- 
perature, 286 
Appert's  method  of  canning  meats,  496- 

498 

^pple,  acid  in,  396 
butter,  453,  454 
composition  of,  395 
crusher,  379 
elevator,  385,  386 
grinder,  379,  380 
jelly,  458,  459 

perfumed,  460,  461 
plant  for  making,  461-165 
juice,  addition  of  benzoate  of  soda 

to,  401 

•  constituents  of,  396 
experiments  to  develop  a  me- 
thod of  sterilizing  399-401 
extraction  of,  by  diffusion,  399 
fermentation  of,  403-406 
fresh,  carbonating  of,  401 
methods  of  obtaining,   378-385 
to  be  fermented,  testing  of.  402, 
marmalade,  perfumed,  457,  458 


Apple  must,  extractive  substances  in,  396 
testing  of,  for  acid  and  sugar, 

387-390 
pomace,  utilization  of,   for  making 

vinegar,  174 

pulp,  preparation  of.  457 
seeds,  saving  of,  465 
wine,  red,  408 

Apples,  bleaching  of,  480.  481 
choice  of,  for  cider,  394,  395 
cider  from,  392-415 
crushing  of,  397 
dried,  chemical  analysis  of,  469 
evaporated,  packing  of,  475,  476 
gathering  and  sweating  of,  396,  397 
paring  of,  480 
pressing  of,  398 
slicing  of,  481 
Apricot  wine.  l.'!4 
Aromatic  mustard,  494 

vinegar,  180,  181 

Artificial  culture  of  vinegar  ferment,  in- 
duction of  the  operation  with.  99-104 
Assmus,   yield  of  products  from   wood 

according  to,  289 

Automatic  principle,  arrangement  of  a 
factory  working  according  to,  90- 

96 
vinegar  apparatus,  73-96 

BACTERIA,  11,  12 
Bacterium  aceti,  1,11 
Pasteurianum,  12 
Bag-filter,  156-158 
Baine-Marie,  436 

Baldwin  apples,  dried,  chemical  analy- 
sis of,  469 

Bamboo,  English,  489,  490 
Barberries,  489 
Barium  acetate,  317-319 
Basic  aluminium  acetates,  320 
cupric  acetates,  332-335 
lead  acetates,  344,  345 
Basilius  Valentinus,  distillation  of  vin- 
egar by,  2 
Beans,  489 
Beech  shavings,  accelerated  acetification 

of,  97-99 
dimensions  of,  53 
drying  of,  54,  55 
for  filling  generators  53-55 
number  of,  required  to  fill  a 

generator,  53 
packing  of,  55 
steaming  of,  54 

vinegar  required   for  acetifica- 
tion of,  96 
Beef,  canned,  498 
extract,  500 


INDEX. 


533 


Beer,  determination   of  vinegar    from, 
230,  231 

for  alcoholic  fluid.  107.  108 
sour,  vinegar  from,  168,  1<>9 
wort,  vinegar  from,  161,  1(52 
Bell  siphon,  89 
Benzoate  of  soda,  addition  of,  to  apple 

juice,  401 

Berries,  jelly  from,  459,  460 
vinegar  from,  169-173 
vinous  fluids  from,  171,  172 
Berry  fruit  pulp,  457 
Bersch's  method  of  making  wine  vine- 
gar, 201-209 
plate  generator,  82-86 
Bioletti,    Frederic    T.,    description    of 
Claudon's      method     of 
making    wine     vinegar 
by,  200,  201 
on   vinegar   from    grapes, 

186,  187 
vinegar    tester     described 

by,  224-2:>6 
Birch  tar  oil,  358,  359 

yield  of  products  from,  289 
Bismuth  acetate,  346 
Blackberry  jelly,  461 

wine,  430,  431 
Black  mordant,  324-326' 
Bleachers,  480,  481 
Boerhave,  method  of  making  wine  by, 

3 

Boiled  tar,  247 
Boiling  of  wine  vinegar,  193 
Bottled  fruits,  sterilizing  of,  436 
Bottling  cider,  408,  409 

wine  vinegar,  209,  210 
Bouquet  bodies,  o 
Box  cooler,  278,  279 
Brandy,    manufacture   of,    from    cider, 

415-418 

Bricking  in  retorts,  264,  265 
Brown  acetate  of  lead,  341 
Biihler,  plant  for  decomposition  of  cal- 
cium acetate  by  the  sulphuric  acid  pro- 
cess arranged  by,  308-310 
Burette,  221 
Burgundy,  412 

from  pear  must,  418,  419 
Burnt  sugar,  preparation  of,  159,  160 

p  ABB  AGE,  489 

'     Cadet-Gassicourt's  process  of  mak- 
ing vinegar  from  sugar,  ]  70 


Calcium  acetate,  317 

decomposition     of,    by    the 
hydrochloric  acid  pro- 
cess, 305-307 
of.  by  the  sulphuric  acid 

process,  307-310 
of,  in  vacuum,  310,  311 
to    aceone    and     cal- 
cium       carbonate, 
352 
evaporating  and  drying  of, 

298 

plant  for  decomposition  of. 
by  the  sulphuric  acid  pro- 
cess, 308-310 
preparation  of,  296-299 

of  sodium  acetate  from, 

303 

Canning  factory,  arrangement  of,  446 
fruits  suitable  and   unsuitable  for, 

439,  440 
meats   by   Appert's   method,    496- 

498 

syrup  for,  442 
tomatoes,  445-449 
vegetables,  444,  445 
Cans,  440 

air-tight,  preserving  in,  438-449 
coating  for  inside,  441 
expulsion  of  air  from,  443 
filling  of,  442 
heating  of,  443,  444 
labeling  of,  448 
manufacture  of,  441,  442 
Caramel,  preparation  of,  159,  160 
Carbo-oven,  262 

Carbonating  fresh  apple  juice,  401 
Carbonic  acid,  377 
Catchups,  449-453 
Cauliflower,  489 
Celery  vinegar,  183 
Cellulose,  changes  in,  234 

effect  of  alkalies  on,  236,  237 

of  sulphuric  acid  on,  235,  236 
Chamber  generator,  Lenze's,  80-82 
Champagne  cider,  410,  411 
Charcoal,  burning  of,  in  heaps,  256 
for  filling  generators,  52 
quantity   of  vinegar    required   for 

acetification  of.  96 
wood  vinegar  and  tar,  preparation 

of.  in  closed  vessels,  254-283 
Cheese,  laying  up  a,  384 
Chemical  examination  of  raw  materials 
and  control  of  operations  in  a  vinegar 
factory,  213-226 
Chillies  in  vinegar,  232 


534 


INDEX.    ' 


Chromic  acetate,  328 
Chromium  acetates,  328 
Chromous  acetate,  328 
Cider,  acidity  in,  413 

adulteration  of,  414,  415 

as  basis  for  artificial  wines,  411,412 

bottling  of,  408,  409 

choice  of  apples  for,  39-1,  395 

clarification  of,  406,  407 

cold  storage  of,  401,  402 

Devonshire,  410 

diseases  of,  412-414 

fermentation  of,  403-406 

fermenting  casks  for,  402,  403 

for  export,  407 

from  apples.  392-415 

greasy  appearance  of,  413 

improving  the  taste  of,  407,  408 

manufacture  of,  378-419 

of  brandy  from,  415-418 
in   the   island   of   Jersey. 

409,  410 

mill,  Hickock's,  378 
pasteurizing  of,  399-401 
plant,  arrangement  of  a,  386,  387 
preparation     of,    like    other    fruit 

wines,  408 
presses,  381-383 
pure,  minimum  of  composition,  for 

414 
sweet,    retarding   fermentation   in, 

399-401 

turbidity  of,  414 
vinegar,  173-178 

home  made,  174-178 
viscosity  of,  413 
wine  from,  408 

Ciders,  analyses  of,    by    United    States 
Agricultural    Department, 
393,  394 
fruit  wines,  etc.,  manufacture  of, 

360-434 

pure,  type  of,  393 
Claret  wine,  41 2 

Claudon's  method  of  making  wine  vin- 
egar, 200,  201 
Cleopatra,  anecdote  of,  1 
Clove  vinegar,  183 
Cobalt  acetate,  328 
Collecting  boxes  for  liquid  products  of 

distillation,  281,  282 
Coloring  vinegar,  159,160 
Combustion,  formation  of  vinegar  a  pro- 
cess of,  32 

Continuous  acting  apparatus,  75,  86 
Coolers,  267,  275-279 
Copper  acetates,  329,  335 

detection  of,  in  vinegar,  229 


Cork  and  cork  waste  for  filling  genera- 
tors, 52 

Corn  cobs  for  filling  generators,  52 

Corned  beef,  498 

Cosmetic  vinegar,  181 

Counter-current  pipe  cooler.  275-278 

Courtenvaux,  experiments  of,  2,  3 

Creosote,  252,  253 

preparation  of,  355-359 

Crusher  for  apples,  H79 

Crystallized  verdigris,  329-332 

Crystallizing  pans  for  sugar  of  lead,  338, 
339 

Cucumber  catchup,  452 

Cucumbers,  489 

Culture,  pure,  of  vinegar  ferment,  100- 

104 
disturbances  in,  103,  104 

Cuprous  acetate,  329 

Currant  catchup,  452 
wine,  422-424 

DAUBREE,  experiments  in   heating 
wood  by,  235 

Davis' s  star  apple  grinder,  379,  380 
Davy,  J.,  discovery  of,  3 
Defecator,  462,  463 
Denies-Dumont,  directions  for  bottling 

cider  by,  408,  409 

Destructive  distillation  of  wood,  execu- 
tion of,  283-290 
products  of,  237-254 
wood  vinegar  and  other 
by-products    obtained 
in,  233-254 
Devonshire  cider,  410 
Diastase,  160 

action  of,  upon  starch,  164 
effective,  164 
formation  of,  37 
Dibasic  cupric  acid  acetate,  333 
Distillation,  destructive,  of  wood,  prod- 
ucts   of, 
237-254 
wood  vinegar 
and  other  by- 
products ob- 
tained       in, 
233-254 

of  cider,  417,  418 
reservoirs  for  the  product  of,  279- 

283 
Distilled  wood  vinegar,  292-296 

purifications  of,  294-296 
Distilling  apparatus  for  sugar  of  lead,  337 

wood  waste,  271-274 
test,  determination  of  alcohol   by, 
215-217 


INDEX. 


535 


Distilling    wood    vinegar    in    multiple 
evaporators  in  vacuum,  293 

Dobereiner,  directions  for  making  vine- 
gar from  sugar  by,  170 
study  of  acetic  acid  by,  3,  6 

Durande,  3 

Diisseldorf  mustard,  494,  495 

EBULLIOSCOPE,   determination    of 
alcohol  by,  217-220 
Effervescing  vinegar,  182,  183 
Eggs,  preservation  of,  503-505 
Elderberry  flowers,  489 

wine.  431 

Elevator  for  apples,  385,  386 
England,    preparation   of    mustard   in, 

492,  493 

English  bamboo,  489,  490 
mustard,  495 
orange  marmalade,  458 
ventilating  apparatus,  61 ,  62 
verdigris,  334,  335 
Ether,  light  oxygenated,  7 
Evaporating  pans,  397 
Evaporation  of  fruit,  465-486 

principle  of,  466-468 
Evaporator,  463 
Evaporators,  470-480 

multiple,  293 

Examination  of  vinegar  as  to  the  pres- 
ence of  foreign  acids  and  of  metals, 
as  well  as  to  its  derivation,  227-232 
Extra-power  cider  press,  382,  383 
Extract  of  lead,  344 

FARMER'S  cider  press,  381,  382 
Fatty  acids  in  wood  vinegar,  242, 

243 
Fermentation,  374-376 

acetic,  products  of,  23-33 

alcoholic,  8,  9 

funnel,  404,  405 

of  fruit  juices,  421 

pectous,  363 

products  of,  374-376 

second,  406 

tumultuous,  404-406 

vinous,  24 

Ferrous  acetate,  324-326 
Fielding,  168 
Filtering  malt  vinegar,  168 

sodium  acetate  solution,  301 

wine  vinegar,  208 
Filters,  155-158 
Filtration  of  vinegar,  155-158 
Fining  vinegar,  159 
Fish,  preservation  of,  502,  503 
Formic  acid,  243 


Foucroy  and  Vauquelin,  3 

Frankfurt  mustard,  494 

French,  modern,  method  of  preparing 

wine  vinegar,  196-200 
mustard,  493 

old,  process  of  making  wine  vine- 
gar, 193-196 
verdigris,  333,  334 
Fresenius,  3,  368 
Fruit  butter,  453,  454 

drying  of,  in  the  oven,  4^5,  486 
evaporated,  packing  of,  475,  476 
evaporation  of,  465-486 
flesh,  preservation  of,  436-438 
juice,  composition  of,  370 
fermentation  of,  421 
free  acid  in,  370 
preservation  of,  435-465 
ripening  of,  a  chemical  process,  365, 

366 

rules  for  preserving,  435,  436 
selection  of,  for  evaporating,  480 

for  wine,  421 
stages  of  development  and  ripening 

of,  367,  368 

sun-drying  apparatus  for,  484,  485 
wines,  additions  to,  360 

clarification  of,  421,  422 
from  stone-fruit,  433,  434 
improving  the  flavor  of.  420 
mixture  of  juices  for,  420 
preparation  of,  419-434 
Fruits  and  their  composition,  368-378 
average  content  of  sugar  and  free 

acid  in,  171 
for  canning,  439,  440 
percentage  of  free  acid  in.  369 

sugar  in,  368 
presses  for,  380-383 
proportion  between  acid,  sugar,  pec- 
tine,  gum  in,  369 
water,   soluble  and 
•  insoluble  substan- 
ces in,  369,  370 
ripening  of,  360-368 
small,  jelly,  from.  459,  460 

wine  from.  419-433 
vinegar  from,  169-173 
Furfurol,  244 
Fusel  oils,  115,  116 

plALLAMOND,  meat  biscuit  accord- 

U    ing  to,  498,  499 

Gas,  yield  of,  from  wood,  241,  242 

Gaseous  combinations  formed  at  differ- 
ent temperatures,  238 
products  of  destructive  distillation 
of  wood,  237-242 


536 


INDEX. 


Gases,  utilization  of,  266,  282,  283 
Generator,  best  form  of,  40 
common  form  of.  41 
comparison  of  a,  to  a  furnace,  35 
controlling  the  work  of  a,  119,  120 
cover  for,  43,  44 
daily   conversion   of    alcohol    into 

acetic  acid  by  a,  31,  32 
development  of  heat  in,  33,  34 
discharge  of  collected  fluid  from, 

45,  46 
distribution  of  alcoholic   fluid  in, 

46-52 
experiments  in  conveying  direct  air 

to  every,  61-63 
for  cider  vinegar,  174 
Lenze's  chamber,  80-82 
Michaelis'  revolving,  72,  73 
plate,  82-86 
protection  of  hoops   and    metallic 

parts  of,  42 

quantity  of  fluid  to  be  worked  in  a, 
•    117, 118 

regulating  the  temperature  in,  36 
Schulze's,  63,  64 
Singer's,  69-72 
sulphuring  a,  138-140 
thermometer  for,  52 
too  feebly  working  of,  129,  130 

vigorously  working  of,  130,  131 
wood  for  construction  of,  41,  42 
Generators,  40-52 

artificial  ventilation  of,  61-73 

cause  of  heating  of,  131 

chemical  examination  of  the  fluid 

running  off  from,  119,  120 
dimensions  of,  42 
filling  the,  52-55 
materials  for  filling,  52,  53 
most  suitable,  43 
sliming  of  shavings  in,  131-133 
with  constant  ventilation  and  con- 
densation, 65-73 
Gerber,  discovery  by,  2 
Gherkins  in  mustard,  491 

pickled,  490,  491 
Glacial  acetic  acid,  3 

preparation    of,    309, 

310,  811,  312 
test  for,  312,  313 
Glucose,  371 ,  390-392 

determination   of    pure   sugar    in, 

391,392 

table    for   finding  content  of    an- 
hydrous sugar  in  saturated  solu- 
tions of,  392 
Glycerin,  376,  377 

for  preserving  eggs.  503,  504 


Glycerin  in  vinegar,  232 
Gooseberry  catchup,  453 
champagne,  427,  429 
wine,  425-427 

Gore,  H.  C.,  experiments  regarding  the 

value  of  peaches  as 

vinegar  stock  by, 

173 

to  develop  a  method 
of  sterilizing  apple 

juice,  399-401 
investigations   by,  of  the  cold 

storage  of  cider,  401,  402 
Gould,  H.  T.,  kiln  evaporator  described 

by,  470-480 
Graduator,  39 
Grain,  fusel  oil  in  spirits  of  wine  from, 

116 

vinegar,  manufacture  of,    162-169 
Grape  must,  potassium  in,  371 

stalks  and  skins  for  refining  malt 

vinegar,  168 

stems  for  filling  generators,  52,  53 
sugar,  371 
Grapes,  conversion  into  raisins,  482 

once  pressed,  after- wine  from,  190- 

192 

vinegar  from,  186.  187 
Grinder  for  apples,  379,  380 
Group  system,  principle  of  the  operation 

of,  122-125 
with  automatic  contrivances, 

operation  of,  125-127 
Gum  in  fruit,  372,  373 
Gumpoldskirchner  mustard,  493 

HALLIDAY'S  apparatus  for  distill- 
ing wood  waste.  271-273 
Ham,  invention  by,  39 
Hannibal,  rocks  dissolved  with  vinegar 

by,  1,  2 
Hassack.  Paul,  preparation  of  after-wine 

according  to.  190-192 
Hassal,  patented  process  of,  502 
Heating  apparatus,  57-59,  95,  96 

utilization  of  gases  for,  266 

vinegar,  153-155 

workroom.  57-59 
Hehner's  alcohol  table,  506-508 
Henry's  vinegar,  181 
Herb  vinegar,  183 
Hickock's  cider  mill.  378 
Hippocrates,  use  of  vinegar  by,  1 
Historical  data.  1-6 
Home-made  cider  vinegar,  174-178 
Horizontal  retorts,  263-267 
Horseradish  catchup,  452 
Hydriodic  acid,  effect  of,  on  wood,  236 


INDEX. 


537 


Hydrocarbons  of  series  CnH2U_6,    prop-  ! 

:erties  of,  250,  251 

Hydrochloric  acid,  detection  of,  in  vin- 
egar, 228 

effect  of,  on  wood,  236 
process    for   decomposi- 
tion  of  calcium   ace- 
tate, 305-308 
Hygienic  mustard,  494 
vinegar,  181 


1 


NORGANIC  constituents,  374 
Iron  acetate,  324-328 

detection  of,  in  vinegar,  229 


JARS.  440 
Jelly,  458-465 
Jersey,  island  of,  manufacture  of  cider 

in,  409,  410 
Juniperberry  wine.  431 

KILN  evaporators,  476-480 
Kilns,  burning  charcoal  in,  256, 

257 

or  ovens  and  retorts,  256-283 
Klar,    apparatus   for    evaporating  and 

drying  calcium  by,  298 
three-still  system  devised  by.  292. 

293 

yield  of  products  from  wood  accord- 
ing to,  289,  290 
Kremser  mustard,  sour,  495 
Kiitzing,   investigation    of    mother    of 
vinegar  by,  21 

LACTIC  acid,  detection  of,  in  vinegar, 
228 

Laragnais,  experiments  of,  2,  3 
Lead  acetates,  335-346 

metallic,  preparation    of  sugar   of 

lead  from,  340.  341 
sesquibasic  acetate,  345 
vinegar,  344 

Lenze's  chamber  generator,  80-82 
Liebig's  theory  of  the  formation  of  vin- 
egar, 7 
Lifting  apparatus  for   vertical  retorts, 

269 

Lime  water,  preserving  eggs  in,  503 
Liquid  products  of  destructive  distilla- 
tion of  wood,  242-254 
Lovage  vinegar,  183 
Low  wine  for  alcoholic  liquid,  111 
Lowitz,  strengthening  of  vinegar  by,  3 


M 


AGNESIUM  acetate,  319,  320 
Malaga  grapes,  482 
wine,  412 


Malic  acid,  396 
Malt,  163,  164 

determination  of  vinegar  from,  230. 

231 
vinegar,  filtering  of,  168 

manufacture  of,  162-169 
Manganese  acetate,  323,  324 
Marc,  wine  vinegar  from,  211,  212 
Marmalade,  454-458 
Mash,  filtration  of,  166,  167 
Mashing,  1(14,  165 

Massonfour's  aerometer  for  must,  527 
Maximum  electrical  thermometer,  59 
Meat  biscuit,  498,  499 

canned,  heating  of,  496,  497 
canning  of,    by  Appert's    method, 

196-498 
fish  and  eggs,  preservation  of,  496- 

505 

powdered,  502 

preparation  of,  for  canning,  496 
quick  salting  of,  500 
quick  smoking  of,  500-502 
Mercuric  acetate,  347 
Mercurous  acetate,  346,  347 
Metacetone,  244 

Metals,  detection  of,  in  vinegar,  229,  230 
Matapectic  acid,  364 
Metapectine,  362 
Methyl  acetate,  properties  of,  249 

alcohol,  243 
preparation  of,  348-352 
properties  of,  249,  250 
Meyer's  system  for  preparing  pure  ace- 
tone, 355 

of  decomposition  of  calcium 
acetate  in  vacuum,  310, 

311 

distilling  wood  vinegar  in 
multiple  evaporators  in 

vacuum,  293 

Michaelis'    revolving  generator,  72,  73 
Minimum  electrical  thermometer,  60 
Mixed  pickles,  490 
Mixture,  104 

Mohr's  volatile  spirits  of  vinegar,  180 
Mold  ferment,  development  of,  101 

formation  of,  198,  199 
Morello  wine,  433 
Mother  of  vinegar,  21,  22,  194 
occurrence  of,  22 
Mothers,  193 
Moutarde  aromatise'e,  495 
aux  Apices,  495 
desjesuites,  493 
de  maille,  495 

Mucilage,  vegetable,  in  fruit,  372,  373 
Mulberry  jelly,  459 


538 


INDEX. 


Mulberry  wine,  431 
Multiple  evaporators,  293 
Mushrooms,  pickled,  491 
Must,  396 

aerometers,  527 

comparative  synopsis  of  aerometers 
for,  526 

testing  of,  for  acid  and  sugar,  387- 

390 
Mustard,  gherkins  in,  491 

preparation  of,  492-495 

vinegar,  183 
Mycoderma,  21 

aceti,  12 

Pasteurianum,  12 

NAPHTHALENE,  properties  of,  251 , 
252 
Neutral  acetate  of  ammonia,  316,  317 

lead,  335-344 
cupric  acetate,  329-332 
ferric  acetate,  326-328 
Nickel  acetate,  328 

Nitric  acid,  detection  of, in  vinegar,  228 
Normal  aluminium  acetate,  320 

OECHSLE'S  aerometer  for  must,  527 
Operations  in   a  vinegar   factory, 

96-104 

Orange  marmalade,  English,  458 
Ordinary  mustard,  493.  494 
Orleans  process  of  making  wine  vinegar, 

193-196 

Oven,  drying  in,  468,  469,  485,  486 
Reichenbach's,  259,  260 
retort,  267 
Schwartz's.  257-259 
Swedish,  260-262 
Ovens,  257-262 

PARAFFIN,  properties  of,  251,  252 
Paring  machines,  480 
Parsnip  wine,  432 

Pasteur,  investigations  by,  8,  11,  12 
liquid  for  the  propagation  of  the 
vinegar    ferment,    recommended 
by, 197 
method  of  preparing  wine  vinegar 

by,  196-200 
Pasteurization,  198 

of  cider,  399-401 
Pasteurizing  bottled  wine  vinegar,  209, 

210 

Pathological  tannin,  374 
Peach  wine,  434 
Peaches  as  vinegar  stock,  173 

pickled,  491 
Pear,  acid  in,  396 


Pear,  cider.  418,  419 
essence,  115,  116 
jelly,  459 

Pears,  drying  of,  in  the  oven,  486 
pVeservation  of,  438 
pickled,  491 
Pectase.  362,  363 
Pectic  acid.  363,  364 
Pectine,  361,  362 
Pectose,  361 
Pectosic  acid,  363 
Pectous  fermentation,  363 

substances  in  fruit,  372 
Pepper  in  vinegar,  232 
Periodically  working  apparatus.  86-90 
Persoon,  investigation  of  mother  of  vin- 
egar by,  21 
Petiot,  process  of,    for  after-wine  from 

grapes  once  pressed,  190-192 
Pettenkofer,  composition  of  wood  gases 

by,  238 
Phosphate,    addition    of,    to    alcoholic 

liquid,  129 

Physiological  tannin,  373,  374 
Picalilli,  490 

Pickled  gherkins,  490,  491 
mushrooms,  491 
onions,  491 
peaches,  491 
peas,  491 
tomatoes,  491 
walnuts,  492 
Pickles,  fruits  and  ingredients  for,  489. 

490 

mixed,  490 

preparation  of.  487-492 
Pineapple  vinegar,  183 
Pipette,  220 
Plate  generator,  82-86 
Platinum  black,   formation  of  vinegar 

by,  9,  10 

preparation     of      vinegar 
with    the   assistance  of, 

148, 149 

Plum  wine,  433,  434 
Plums,  treatment  of,  after  evaporating. 

482 
Potato  alcohol  for  making  vinegar.  116 

fusel  oil,  115,  116 
Potatoes,  evaporating  of,  483,  484 
Potassium  acetate,  314-316 
acid  acetate,  316 
bitartrale,  371 
diacetate,  316 

Powdered  meat,  preparation  of,  502 
Preservation  of  fruit,  435-465 
Preserving  in  air-tight  cans,  '438-449 
Press  cloths,  398 


INDEX. 


539 


Presses,  380-383 

Preventive  vinegar,  181 

Products,  yield  of,  from  wood,  288-290 

Prunes,  drying  of,  in  the  oven,  485,  486 

Pumice  for  filling  generators,  52 

Pyroligneous  acid,  3 

U1CK  process  of  manufacture  of  vin- 
egar, 
39-55 

wine   vinegar  by 
the,  210,  211 


Q 


Quince  wine,  419 

EACKS,  383-385 
Raisin  stalks  and  skins  for  refin- 
ing malt  vinegar,  168 
Raisin^,  454 
Kape  vessels,  168 
Raspberry  jelly,  461 
vinegar,  183.  184 
wine,  429,  430 

Raw   materials,   chemical    examination 
of,  and  control  of  operations  in  a 
vinegar  factory,  213-226 
tar.  247 
Red  apple  wine,  408 

mordant,  320 
Refining  vessels,  168 
Reichen bach's  oven,  259,  260 
Reservoirs  for  the   product   of  distilla- 
tion, 279-283 
Retort-ovens,  arrangement  of,  268-271 

tar,  247 
Retorts,  262-271 

bricking  in  of,  264,  265 
horizontal,  263-267 
vertical,  267-271 
wrought  iron,  283-266 
Rhubarb  wine,  432 
River  water,  115 
Rothe.  experiments  by,  289 

method    for   purification    of  wood 
vinegar  by,  294-296 

OACCHAROMETER,  use  of,  in  jelly 
O     boiling,  459 
Saccharometers,  213 
Saccharomyces  ellipsoidus,  403 

mesembryanthemum.  13 
Sackett,  Walter  G.,  directions  for  home- 
made cider  vinegar  by,  174-178 
Salting  meat,  quick,  500 
Sand,  filtering,  156 
Saussure.  determination  of  the  chemical 

constitution  of  alcohol  by,  3 
Schizomycetes,  11,  12 
Schiibler    and    Neuffler,    quantities    of 

water  in  wood  found 'by,  233 


Schulze's  generator,  63,  61 

ventilating  apparatus,  63-65 
Schutzenbach,  introduction  of  the  quick 

process  by,  3,  39 
Schwartz's  oven,  257-259 
Sesquiacetate  of  iron,  326-328 
Sesquibasic  cupric  acetate,  332 
Sexbasic  acetate  of  lead,  346 
Shavings,    accelerated    acetification   of, 

97-99 

effect  of  sodium  sulphide  on,  237 
quantity  of  vinegar  for  acetification 

of,  96 

saturation  of,  with  vinegar,  99 
sliming  of,  131-135 
Sherry  wine,  412 
Silicate  of  soda  for  preserving  eggs,  504, 

505 

Silver  acetate,  347.  348 
Singer's  generator,  69-72 
Siphon  barrel,  88,  89 
Slicers,  481 

Sliming  of  shavings.  131-135 
Slow  process  of  making  vinegar,  143- 

149 
Smoking  meat,  quick  process  of,  500- 

502 

Soda  test  liquor,  221 
Sodium  acetate.  316 

preparation  of,  299-304 
sulphide,  effect  of,  on  shavings,  237 
Soup  tablets,  499,  500 
Sparger,  50-52 
Spirits  of  wine,  115 

content  of  alcohol  in,  112 
determination    of  true 
strengths  of,  513-518 
of  vinegar  from,  230 
fusel  oils  in,  115,  116 
specific  gravity  of,  112 
Stahl,  strengthening  vinegar  by.  2 
Starch,  action  of  diastase  upon,  164 

vinegar  from,  160.  161 
Starr.   Richard   T. .   canning    tomatoes 

described  by,  445-449 
Stein's  method  of  preparing   sugar  of 

lead.  337-340 
Still  for  rectification  of  wood  spirit.  349, 

350 
Stolze,  methods  for  purification  of  wood 

vinegar  by,  294 

yield  of  products  from  wood  accord- 
ing to.  288.  290 
Stone  fruit,  evaporating  of,  482 
jelly  from,  460 
wine  from,  433,  434 
Stoves,  167 
Strawberry  jelly,  461 


540 


INDEX. 


Strawberry  wine,  424,  425 
Strontium  acetate,  319 
Succinic  acid,  376 

in  vinegar,  232 

wine,  376 

Sugar  beets,  vinegar  from.  169 
determination  of,  213 
of  lead,  335-344 
testing  must  for.  387-390 
vinegar  from,  169,  170 
Sulphuric  acid,  detection  of.  in  vinegar, 

227,  228 
effect  of,  on  cellulose,  235. 

236 

process  for  decomposition 
of  calcium  acetate,  305- 
308 
Sulphuring  generators,  138-140 

vinegar.  158.  159 

Sulphurous  acid,  detection  of,  in  vine- 
gar, 228,  229 

Sun-drying  apparatus,  484,  485 
Swedish  oven.  260-262 
Syrup  for  canning,  442 

TABLE  for  comparing  different  aerom- 
eters with  Tralles's 

alcoholometer,    512 
percent,  of  sugar  with 
per  cent,  of  extract 
and    the    specific 
gravity,  527 
Reau  mui's,        Cel- 
sius's, and  Fahr- 
enheit's    ther- 
mometers, 

530 

determining   content    of  per 
cent,    of  acetic   acid   con- 
tained in  a  vinegar,  528, 

529 

determination  of  true  volume 

of    alcoholic 

fluids  from 

apparent 

volume. 

520 

true  strengths 
of    spirits, 

514-518 

reduction  of  specific  gravities 
to  saccharometer  per  cent., 

523-525 

Hehner's  alcohol,  506-508 
of  actual  content  of  alcohol  and 
water    in    mixtures    of 
both  fluids.and  contrac- 
tion in  mixing,  511 


Table  of  comparative  synopsis  of  aero- 
meters for  must,  526 
proportion  between  per  cent,   by 
weight  and  by  volume  of  alco- 
holic fluids,  510 

specific  gravity  of  mixtures  of  al- 
cohol and  water,  509 
to  Massonfoar's  aerometer,  527 

Oechsle's  aerometer  for  must,  527 
vinegars,  181-184 
Tannin  in  fruit,  373,  374 
Tar,  244-248 

oils,  preparation  of  355-359 
products  of  distillation  of,  356,  357 

properties  of,  250-254 
separation  of,  from  wood  vinegar. 291 
Tarragon  vinegar,  182 
Tartar,  crude,  371 

Tereil  and  Chateau,  method  for  purifica- 
tion of  wood  vinegar  by,  294 
Terrace  system,  75-80 
Thenard,  demonstration  by,  3 
Thermometer,  maximum  electrical,  59 

minimum  electrical,  60 
Thermometers,  comparison  of,  530 
Three-group  system,  8(5-96 
Three-still  system,  292,  293 
Tilting  trough,  49 

modification  of,  86-88 
Tin  acetate,  346 
cans,  440,  441 

detection  of,  in  vinegar,  229.  230 
Toilet  vinegars,  180,  181 
Tomato  catchup,  450,  451 

wine,  432 

Tomatoes,  canning  of,  445-449 
evaporating  of,  482,  483 
pickled,  491 
Tower  evaporators,  470-474 

drying  in,    482 
Tralles's  alcoholometer,   comparison    o 

different  aerometers  with.  512 
Tribasic  acetate  of  lead.  345,  346 

cupric  acetate,  333 
Triplumbic  tetracetate,  345 
Tutti-frutti,  458 

TTRANIUM  acetate,  346 

VATS  for  liquid  products  of  distilla- 
tion, 279-281 

Vegetable  mucilage  in  fruit,  372,  373 
Vegetables,  canning  of,  444,  445 
Ventilating  apparatus,  English,  61,  62 

Schulze's,  63-65 
Ventilation,  artificial  of  generators,  61- 


INDEX. 


541 


Ventilation     constant,     and    condensa- 
tion, generators  with,  65-73 
Verdigris,  338-335 

crystallized,  329-332 
Vertical  retorts,  267-271 
Vidal-Malligaud's  ebullioscope,  218, 

219 

Vinaigre  des  quatre  voleurs,  181 
Vinegar,  acme  of  formation  of,  33 
addition  of  volatile  oils  to,  5 
apparatus,  automatic,  73-96 

continuously  working,  75-86 
periodically  working,  86-90 
bacteria,  factors  for  the  settlement 

of,  upon  a  fluid,  16,  17 
rapidity   of  propagation  of, 

It) 

coloring,  159,  160 
conversion  of  wine  into,  13-15 
derivation  of,  230-232 
determination    of    acetic   acid    in, 
113,  528,  529 
anhydride  in, 
220-224 

difference  in,   from   various  mate- 
rials, 37 

disturbing  influences  in  the  manu- 
facture of,  128-142 
eels,  appearance  of,  in  making  wine 

vinegar,  199 

disturbances  due  to,  135-140 
remedies  for  the  suppression  of, 

137-140 

structure  of,  135,  136 
essence,  4,  5 

examination  of,  as  to  the  presence 
of  foreign  acids  and  of  metals,  as 
well  as  to  its  derivation,  227-232 
factory,  arrangement  of  a,  56-60 
chemical   examination  of  raw 
materials     and     control     of 
operations  in  a,  213-226 
operations  in  a,  96-104,  116- 

127 

working  according  to  the  auto- 
matic    principle,     arrange 
ment  of,  90-96 
ferment,  8 

and  its  conditions  of  life,  13-23 
composition   of  nutrient   fluid 

for,  17-19 
conditions    for    nutriment    of, 

16-20 

constitution  of,  23 
disturbances  in  pure  culture  of, 

103,  104 

effect   of    defective   nutriment 
on,  128,  129 


Vinegar  ferment,  effect  of  temperature 

on,  19,  20 
fluids   for    the    nutriment  of, 

100,  101 

induction    of    operation    with 
artificial  culture  of,  99-104 
origin  of,  13 

Pasteur's  liquid  for  the  propa- 
gation of,  197 
pure  culture  of,  100-104,  201, 

202 

sensitiveness  of,  74 
supply  of  air  for,  19 
field,  193 

filtration  of,  155-158 
fining,  159 
for  domestic  use,  170 
formation  of  acetic  ether  in,  184 
of,  by  fermentation,  a  chemico- 

physiological  process,  23 
freshly-prepared,  further  treatment 

of,  149-160 
odor  of,  149 

from  beer-wort,  161,  162 
starch,  160,  161 
sugar  beets,  169 
various  materials,  preparation  of, 

160-178 

wine,  composition  of,  187,  188 
heating  of,  153-155 
high-graded,  107 
historical  data  on,  1-6 
household    manufacture    of,     147, 

148  , 

improving  the  odor  of,  150,  151 
induction  of  the  formation  of,  143 
introduction  of  the  quick  process  of 

making,  3,  39 

lice,  disturbances  due  to,  140-142 
Liebig's   theory  of  the  formation 

of,  7 

materials  for.  36,  37 
methods  of  manufacture  of,  36-38 
mites,  disturbances  due  to.  140-142 
ordinary,  constitution  of,  1 
perfumed,    dissolving   volatile   oils 

for,   178-180 
points  of  theoretical  conditions  of 

formation  of,  22,  23 
preparation  of,  with  platinum  black, 

148, 149 
principal     defects    of    manner    of 

manufacturing,  5,  6 
production  of  strongest,  121,  122 
progress  essential  for  the  manufac- 
turer of,  4 

quantity    of,    for     acetification    of 
shavings,  96 


542 


INDEX. 


Vinegar,  quick  process  of  manufacture, 

39-55 

role  of,  in  alcoholic  fluid,  105 
saturation  of  shavings  with,  99 
specialties,  178-185 
spiced,  488 
stock,  peaches  as,  173 
stored,  constituents  of,  151-153 

removal  of  sediment  from,  151 
sulphuring,  158,  159 
tester,  224-226 
theory  of  formation  of,  6-1 2 
time  for  making,  by  slow  process, 

145 

yeast,  8 
Vinous  fermentation,  24 

products  of,  375-378 
Vitruvius,  2 
Volkel's  method  of  preparing  sugar  of 

lead,  335 

Volumetric   analysis,  determination   of 
acetic  acid  by,  222-224 

WAGMANN,  invention  by,  39 
Walnut  catchup,  451,  452 
Wash,  104,  114 

preparation  of,  143,  144 
Water  glass  for  preserving  eggs,  504, 505 
Well-waters,  114 
White  lead,  344 
Williams  evaporator,  472-474 
Wine,  acetic  degeneration  of,  189,  190 
acetificatiou  of,  202 
composition  of,  187,  188 
conversion  of,  into  vinegar,  18-15 
definition  of,  360 

determination  of  vinegar  from,  231 
from  cider,  408 

small  fruits,  419-433 
glycerin  in,  376 
mustard,  494 
sick,  188,  189 
slow  acetification  of,  192 
succinic  acid  in,  376 
vinegar  by  the  quick  process,  210, 

211 
bottled,   pasteurizing    of,  209, 

210 

bottling,  209,  210 
composition  of,  187,  188 
disturbances  in  the  production 

of,  208 
factory,   operations  in  a,   206, 

207 

filtering,  208 
from  marc,  211,  212 
manufacture  of,  186  212 
oldest  method  for  making,  193 


Wine  vinegar,  potassium  bitartrate  in, 

231 

reasons  for  superiority  of,  187 
storage  of,  208 
vats  foi-  ruaking,  204 
yeast,  elliptic,  403 
Wines,  artificial,  cider  as  basis  for,  411, 

412 

best,  for  making  vinegar,  203 
Witherite,  preparation  of  barium  acetate 

from,  317-319 
Wood,  air-dry,  average  composition  of, 

234 

percentage  of  water  in ,  98 
yields  from,  247,  248 
constitution  of,  233,  234 
decomposition  of,  234-237 
destructive    distillation    of.   bodies 
appearing 
in.  246 

execution  of,  283-296 
properties   of    combi- 
nations  formed   in. 
248-254 
effect  of  chemicals  on,  235-237 

heating  on,  235 
gases,  composition  of,  238 
illuminating  gases  from,  253 
installation  of  plant  for  utilizing,  in 
a  thermo-chemical  way,  254-256 
preservation  of,  234,  235 
spirit  for  denaturing,  351,  352 
preparation  of.  348 
properties  of,  249.  250 
rectification  of,  349,  350 
specific  gravity  of,  233,  234 
tar,  244-248 

character  of,  247 
combinations  in,  244-246,  253, 

254 

creosote,  252,  253 
distillation  of.  355,  356 
products  of  distillation  of,  356, 

357 

separation  of  various  combina- 
tions in,  24(5.  247 
working  the,  855-359 
yield  of,  246 
vinegar,  242-244 

and  other  by-products  obtained 
in  the  destructive  distillation 
of  wood,  233-254 
constituents  of,  292 
distilled,  292-296 

purification  of,  294-296 
distilling  of,  in  multiple  evap- 
orators in  vacuum,  293 
fatty  acids  in,  242,  243 


INDEX. 


543 


Wood  vinegar,  freshly   prepared,  pro- 
perties of,  293,  294 
production  of  pure  acetic  acid 

from,  296-313 
separation  of  tar  from,  291 
treatment  of,  290-313 
waste,  distilling  apparatus  for,  271- 

274 

water  in,  233 
yield  of  gas  from,  241 ,  242 


Wood,   yield    of    wood    vinegar   from, 

244 

yields  of  products  from,  288-290 
Workroom,  control  of  temperature  iir, 

59,60 

heating  the,  57-59 
principal  requisites  for,  56 


Z 


INC  acetate,  329 


CATALOGUE 

OF 

Practical  and  Scientific  Books 


PUBLISHED    BY 


Henry  Carey  Baird  &  Co. 

INDUSTRIAL  PUBLISHERS,   BOOKSELLERS  AND  IMPORTERS 

810  Walnut  Street,  Philadelphia. 


S"  Any  of  the  Books  comprised  in  this  Catalogue  will  be  sent  by  mail, 
free  of  postage,  to  any  address  in  the  world,  at  the  publication  prices, 

®=  A   Descriptive   Catalogue,  94    pages,  8vo,  will  be  sent  free  and  free 
of  postage,  to  any  one  in  any  part  of  the  world,  who  will  furnish  his 
address. 

®"  'Where    not    otherwise    stated,    all    of  the  Books  in  this  Catalogue 
are  bound  in  muslin. 


AMATEUR  MECHANICS'  WORKSHOP: 

A  treatise  containing  plain  and  concise  direction  for  the 
manipulation  of  Wood  and  Metals,  including  Casting,  Forg- 
ing, Brazing,  Soldering  and  Carpentry.  By  the  author  of 
the  "Lathe  and  Its  Uses."  Seventh  edition.  Illustrated. 
8vo $1.50 

AR  ^OT.— A  Complete  Guide  for  Coach  Painters: 

Translated  from  the  French  of  M.  ARLOT,  Coach  Painter,  for 
eleven  years  Foreman  of  Painting  to  M.  Eherler,  Coach 
Maker,  Paris  By  A.  A.  FESQUET,  Chemist  and  Engineer. 
To  which  is  added  an  Appendix,  containing  Information  re- 
specting the  Materials  and  the  Practice  of  Coach  and  Car 
Painting  and  Varnishing  in  the  United  States  and  Great 
Britain.  12mo . .  $1.25 


2        HENRY  CAREY  BAIRD  &  GO'S.  CATALOGUE 

ARMENGAUD,  AMOROUX,  AND  JOHNSON.— The  Prac- 
tical Draughtsman's  Book  of  Industrial  Design,  and 
Machinist's  and  Engineer's  Drawing  Companion: 

Forming  a  Complete  Course  of  Mechanical  Engineering  and 
Architectural  Drawing.  From  the  French  of  M.  Armengaud 
the  elder,  Prof,  of  Design  in  the  Conservatoire  of  Arts  and 
Industry,  Paris,  and  M.  Armengaud  the  younger,  and  Amo- 
roux,  Civil  Engineers.  Rewritten  and  arranged  with  addi- 
tional matter  and  plates,  selections  from  and  examples  of 
the  most  useful  and  generally  employed  mechanism  of  the 
day.  By  WILLIAM  JOHNSON,  Assoc.  Inst.  C.  E.  Illustrated 
by  fifty  folio  steel  plates,  and  fifty  wood-cuts.  A  new  edi- 
tion, 4to.,  cloth $5.00 

ARROWSMITH.— The  Paper-Hanger's  Companion 

Comprising  Tools,  Pastes,  Preparatory  Work;  Selection  and 
Hanging  of  Wall-Papers ;  Distemper  Painting  and  Cornice- 
Tinting;  Stencil  Work;  Replacing  Sash-Cord  and  Broken 
Window  Panes;  and  Useful  Wrinkles  and  Receipts.  By 
JAMES  ARROWSMITH.  A  New,  Thoroughly  Revised,  and 
Much  Enlarged  Edition.  Illustrated  by  25  engravings,  162 
pages.  (1905) $1.00 

ASHTON.— The  Theory  and  Practice  of  the  Art  of  Design- 
ing Fancy  Cotton  and  Woolen  Cloths  from  Sample: 

Giving  full  instructions  for  reducing  drafts,  as  well  as  the 
methods  of  spooling  and  making  put  harness  for  cross  drafts 
and  finding  any  required  reed;  with  calculations  and  tables 
of  yarn.  By  FREDERIC  T.  ASHTON,  Designer,  West  Pittsfield, 
Mass.  With  fifty-two  illustrations.  One  vol.  folio $4.00 

ASKINSON.— Perfumes  and  their  Preparation: 

A  Comprehensive  Treatise  on  Perfumery,  containing  Com- 
plete Directions  for  Making  Handkerchief  Perfumes,  Smelling- 
Salts,  Sachets,  Fumigating  Pastils;  Preparations  for  the  Care 
of  the  Skin,  the  Mouth,  the  Hair;  Cosmetics;  Hair  Dyes,  and 
other  Toilet  Articles.  By  G.  W.  ASKINSON.  Translated 
from  the  German  by  ISIDOR  FURST.  Revised  by  CHARLES 
RICE.  32  illustrations.  8vo $3.00 

BAIRD. — The  American  Cotton  Spinner,  and  Manager's 
and  Carder's  Guide:  • 

A  Practical  Treatise  on  Cotton  Spinning;  giving  the  Dimen- 
sions and  Speed  of  Machinery,  Draught  and  Twist  Calcula- 
tions, etc;  with  notices  of  recent  Improvements;  together 
with  Rules  and  Examples  for  making  changes  in  the  size  and 
numbers  of  Roving  and  Yarn.  Compiled  from  the  papers 
of  the  late  ROBERT  H.  BAIRD.  256  pp.,  12mo $1.50 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE       3 

BEANS. — A  Treatise  on  Railway  Curves  and  Location  of 
Railroads: 

By  E.  W.  BEANS,  C.  E.    Illustrated.      12mo.    Morocco  $1.00 
BELL. — Carpentry  Made  Easy: 

Or,  The  Science  and  Art  of  Framing  on  a  New  and  Improved 
System.  With  Specific  Instructions  for  Building  Balloon 
Frames,  Barn  Frames,  Mill  Frames,  Warehouses,  Church 
Spires,  etc.  C9mprising  also  a  System  of  Bridge  Building, 
with  Bills,  Estimates  of  Cost,  and  valuable  Tables.  Illus- 
trated by  forty- four  plates,  comprising  nearly  200  figures. 
By  WILLIAM  E.  BELL,  Architect  and  Practical  Builder. 
8vo $5.00 

BERSCH.— Celluose,    Cellulose     Products,    and    Rubber 

Substitutes: 

Comprising  the  Preparation  of  Cellulose,  Parchment-Cellu- 
lose, Methods  6f  Obtaining  Sugar,  Alcohol,  and  Oxalic  Acid 
from  Wood-Cellulose;  Production  of  Nitro-Cellulose  and  Cellu- 
lose Esters;  Manufacture  of  Artificial  Silk,  Viscose,  Celluloid, 
Rubber  Substitutes,  Oil-Rubber,  and  Faktis.  By  Dr.  JOSEPH 
BERSCH.  Translated  by  WILLIAM  T.  BRANNT.  41  Illustra- 
tions. (1904) $3.00 

BILLINGS.— Tobacco: 

Its  History,  Variety,  Culture,  Manufacture,  Commerce,  and 
Various  Modes  of  Use.  By  E.  R.  BILLINGS.  Illustrated  by 
nearly  200  engravings.  8vo $3.00 

BIRD. — The  American  Practical  Dyers'  Companion: 

Comprising  a  Description  of  the  Principal  Dye-Stuffs  and 
Chemicals  used  in  Dyeing,  their  Nature  and  Uses;  Mordants 
and  How  Made;  with  the  best  American,  English,  French 
and  German  processes  for  Bleaching  and  Dyeing  Silk,  Wool, 
Cotton,  Linen,  Flannel,  Felt,  Dress  Goods,  Mixed  and 
Hosiery  Yarns,  Feathers,  Grass,  Felt,  Fur,  Wool,  and 
Straw  Hats,  Jute  Yarn,  Vegetable  Ivory,  Mats,  Skins,  Furs, 
Leather,  etc.,  etc.,  by  Wood,  Aniline,  and  other  Processes, 
together  with  Remarks  on  Finishing  Agents,  and  Instructions 
in  the  Finishing  of  Fabrics,  Substitutes  for  Indigo,  Water- 
Proofing  of  Materials,  Tests  and-  Purification  of  Water. 
Manufacture  of  Aniline  and  other  New  Dye  Wares,  Harmoniz- 
ing Colors,  etc.,  etc.,;  embracing  in  all  over  800  Receipts  for 
Colors  and  Shades,  accompanied  by  170  Dyed  Samples  of  Raw 
Materials  and  Fabrics.  By  F.  J.  BIRD,  Practical  Dyer, 
Author  of  "The  Dyers'  Hand-Book. "  8vo $4.00 

BLINN. — A    Practical    Workshop    Companion    for    Tin, 
Sheet-Iron,  and  Copper-plate  Workers: 

Containing  Rules  for  describing  various  kinds  of  Patterns 


4       HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

used  by  Tin,  Sheet- Iron  and  Copper-plate  Workers;  Practical 
Geometry;  Mensuration  of  Surface  and  Solids;  Tables  of  the 
Weights  of  Metals,  Lead-pipe,  etc".;  Tables  of  Areas  and 
Circumferences  of  Circles;  Japan,  Varnishes,  Lacquers,  Ce- 
ments, Compositions,  etc.,  etc.  By  LEROY  J.  BLINN,  Master 
Mechanic.  With  One  Hundred  and  Seventy  Illustrations. 
12mo $2.50 

BOOTH.— Marble  Worker's  Manual: 

Containing  Practical  Information  respecting  Marbles  in 
general,  their  Cutting,  Working  and  Polishing;  Veneering  of 
Marble;  Mosaics;  Composition  and  Use  of  Artificial  Marble, 
Stuccos,  Cements,  Receipts,  Secrets,  etc.,  etc.  Translated 
from  the  French  by  M.  L.  BOOTH.  With  an  Appendix  con- 
cerning American  Marbles.  12mo.,  cloth  $1.50 

BRANNT. — A  Practical  Treatise  on  Animal  and  Vegetable 
Fats  and  Oils: 

Comprising  both  Fixed  and  Volatile  Oils,  their  Physical  and 
Chemical  Properties  and  Uses,  the  Manner  of  Extracting  and 
Refining  them,  and  Practical  Rules  for  Testing  them;  as  well 
as  the  Manufacture  of  Artificial  Butter  and  Lubricants,  etc., 
with  lists  of  American  Patents  relating  to  the  Extraction, 
Rendering,  Refining,  Decomposing  and  Bleaching  of  Fats 
and  Oils.  By  WILLIAM  T.  BRANNT,  Editor  of  the  "Techno- 
Chemical  Receipt  Book."  Second  Edition,  Revised  and 
in  great  part  Rewritten.  Illustrated  by  302  Engravings. 
In  Two  Volumes.  1304pp.  8vo $10.00 

BRANNT. — A  Practical  Treatise  on  Distillation  and  Rec- 
tification of  Alcohol: 

Comprising  Raw  Materials;  Production  of  Malt,  Preparation 
of  Mashes  and  of  Yeast;  Fermentation;  Distillation  and 
Rectification  and  Purification  of  Alcohol;  Preparation  of 
Alcoholic  Liquors,  Liqueurs,  Cordials,  Bitters,  Fruit  Essences, 
Vinegar,  etc.;  Examination  of  Materials  for  the  Preparation 
of  Malt  as  well  as  of  the  Malt  itself;  Examination  of  Mashes 
before  and  after  Fermentation;  Alcoholometry,  with  Numer- 
ous Comprehensive  Tables;  and  an  Appendix  on  the  Manu- 
facture of  Compressed  Yeast  and  the  Examination  of  Alcohol 
and  Alcoholic  Liquors  for  Fusel  Oil  and  other  Impurities 
By  WILLIAM  T.  BRANNT,  Editor  of  "The  Techno-Chemical 
Receipt  Book."  Second  Edition.  Entirely  Rewritten.  Il- 
lustrated by  105  engravings.  460  pages.  8vo.  (Dec., 
1903) $10.00 

BRANNT. — India  Rubber,  Gutta-Percha  and  Balata: 

Occurrence,  Geographical  Distribution,  and  Cultivation,  Ob- 
taining and  Preparing  the  Raw  Materials,  Modes  of  Working 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE       5 

and  Utilizing  them,  including  Washing,  Maceration,  Mixing, 
Vulcanizing,  Rubber  and  Gutta-Percha  Compounds,  Utiliza- 
tion of  Waste,  etc.  By  WILLIAM  T.  BRANNT.  Illustrated. 
12mo.  A  new  edition  in  preparation. 

BRANNT. — A  Practical  Treatise  on  the  Manufacture  of 
Vinegar  and  Acetates,  Cider,  and  Fruit- Wines: 

Preservation  of  Fruits  and  Vegetables  by  Canning  and  Evap- 
oration; Preparation  of  Fruit-Butters,  Jellies,  Marmalades, 
Catchups,  Pickles,  Mustards,  etc.  Edited  from  various 
sources.  By  WILLIAM  T.  BRANNT.  Illustrated  by  79  En- 
gravings. 479  pp.  8vo (Scarce) 

BRANNT.— The  Metallic  Alloys:  A  Practical  Guide: 

For  the  Manufacture  of  all  kinds  of  Alloys,  Amalgams,  and 
Solders,  used  by  Metal  Workers:  together  with  their  Chem- 
ical and  Physical  Properties  and  their  Application  in  the  Arts 
and  the  Industries;  with  an  Appendix  on  the  Coloring  of 
Alloys  and  the  Recovery  of  Waste  Metals.  By  WILLIAM 
T.  BRANNT.  45  Engravings.  Third,  Revised,  and  Enlarged 
Edition.  570  pages.  8vo Net,  $5.00 

BRANNT.— The  Metal  Worker's  Handy-Book  of  Receipts 
and  Processes: 

Being  a  Collection  of  Chemical  Formulas  and  Practical 
Manipulations  for  the  working  of  all  Metals;  including  the 
decoration  and  Beautifying  of  Articles  Manufactured  there- 
from, as  well  as  their  Preservation.  Edited  from  various 
sources.  By  WILLIAM  T.  BRANNT.  Illustrated.  12mo.$2.50 

BRANNT.— Petroleum : 

Its  History,  Origin,  Occurrence,  Production,  Physical  and 
Chemical  C9nstitution,  Technology,  Examination  and  Uses; 
Together  with  the  Occurrence  and  Uses  of  Natural  Gas. 
Edited  chiefly  from  the  German  of  Prof.  Hans  Hoefer  and  Dr. 
Alexander  Veith  by  Wm.  T.  BRANNT.  Illustrated  by  3 
Plates  and  284  Engravings.  743pp.  8vo $12.50 

BRANNT. — The    Practical    Dry     Cleaner,     Scourer    and 
Garment  Dyer: 

Comprising  Dry,  Chemical,  or  French  Cleaning;  Purifica- 
tion of  Benzine;  Removal  of  Stains,  or  Spotting;  Wet  Clean- 
ing; Finishing  Cleaned  Fabrics;  Cleaning  and  Dyeing  Furs, 
Skin  Rugs  and  Mats;  Cleaning  and  Dyeing  Feathers;  Clean- 
ing and  Renovating  Felt,  Straw  and  Panama  Hats;  Bleach- 
ing and  Dyeing  Straw  and  Straw  Hats;  Cleaning  and  Dyeing 
Gloves;  Garment  Dyeing;  Stripping;  Analysis  of  Textile 
Fabrics.  Edited  by  WILLIAM  T-  BRANNT,  Editor  of  "The 
Techno-Chemical  Receipt  Book."  Fourth  Edition,  Revised 


6       HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

and  Enlarged.    Illustrated  by  Forty-One  Engravings.    12 

mo.     371   pp $2.50 

CONTENTS :  I.  Dry  Chemical  or  French  Cleaning.  II.  Removal 
of  Stains  or  Spotting.  III.  Wet  Washing.  IV.  Finishing  Cleaned 
Fabrics.  V.  Cleaning  and  Dyeing  Furs,  Skin  Rugs  and  Mats.  VI. 
Cleaning  and  Dyeing  Feathers.  VII.  Cleaning  and  Renovating  Felt, 
Straw  and  Panama  Hats ;  Bleaching  and  Dyeing  Straw  and  Straw 
Hats.  VIII.  Cleaning  and  Dyeing  Gloves.  IX.  Garment  Dyeing. 
X.  Stripping  Colors  from  Garments  and  Fabrics.  XI.  Analysis  of 
Textile  Fabrics.  Index. 

BRANNT. — The  Soap  Maker's  Hand-Book  of  Materials, 

Processes  and  Receipts  for  every  description  of  Soap;  includ- 
ing Fats,  Fat  Oils  and  Fatty  Acids;  Examination  of  Fats  and 
Oils;  Alkalies;  Testing  Soda  and  Potash;  Machines  and 
Utensils;  Hard  Soaps;  Soft  Soaps;  Textile  Soaps;  Washing 
Powders  and  Allied  Products;  Toilet  Soaps,  Medicated 
Soaps,  and  Soap  Specialties;  Essential  Oils  and  other  Perfum- 
ing Materials;  Testing  Soaps.  Edited  chiefly  from  the  Ger- 
man of  DR.  C.  DEITE,  A.  ENGELHARDT,  F.  WILTNER,  and 
numerous  other  Experts.  With  Additions  by  WILLIAM  T. 
BRANNT,  Editor  of  "The  Techno-Chemical  Receipt  Book." 
Illustrated  by  Fifty-four  Engravings.  Second  edition,  Re- 
vised and  in  great  part  Re- Written.  535  pp.  8vo $6.00 

BRANNT. — Varnishes,  Lacquers,  Printing  Inks  and  Seal- 
ing Waxes: 

Their  Raw  Materials  and  their  Manufacture,  to  which  is 
added  the  Art  of  Varnishing  and  Lacquering,  including  the 
Preparation  of  Putties  and  of  Stains  for  Wood,  Ivory,  Bone, 
Horn,  and  Leather.  By  WILLIAM  T.  BRANNT.  Illustrated 
by  39  Engravings,  338  pages.  12mo $3.00 

BRANNT-WAHL.— The  Techno-Chemical  Receipt  Book: 

Containing  several  thousand  Receipts  covering  the  latest, 
most  important,  and  most  useful  discoveries  in  Chemical 
Technology,  and  their  Practical  Application  in  the  Arts  and 
the  Industries.  Edited  chiefly  from  the  German  of  Drs. 
Winckler,  Eisner,  Heintze,  Mierzinski,  Jacobsen,  Koller  and 
Heinzerling,  with  additions  by  WM.  T.  BRANNT  and  WM.  H. 
WAHL,  Ph.  D.  Illustrated  by  78  engravings.  12mo.  495 
pages $2.00 

BROWN. — Five  Hundred  and   Seven  Mechanical  Move- 
ments : 

Embracing  all  those  which  are  most  important  in  Dynamics, 
Hydraulics,  Hydrostatics,  Pneumatics,  Steam  Engines,  Mill 
and  other  Gearing,  Presses,  Horology,  and  Miscellaneous 
Machinery;  and  including  many  movements  never  before 
published,  and  several  of  which  have  only  recently  come  into 
use.  By  HENRY  T.  BROWN $1.00 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE       7 

BULLOCK.— The  Rudiments  of  Architecture  and  Build- 
ing: 

For  the  use  of  Architects,  Builders,  Draughtsmen,  Machin- 
ists, Engineers  and  Mechanics.  Edited  by  JOHN  BULLOCK, 
author  of  "The  American  Cottage  Builder."  Illustrated 
by  250  Engravings.  8vo $2.50 

BYRNE. — Hand-Book   for   the   Artisan,    Mechanic,    and 
Engineer: 

Comprising  the  Grinding  and  Sharpening  of  Cutting  Tools, 
Abrasive  Processes,  Lapidary  Work,  Gem  and  Glass  En- 
graving, Varnishing  and  Lacquering,  Apparatus,  Materials 
and  Processes  for  Grinding  and  Polishing,  etc.  By  OLIVER 
BYRNE.  Illustrated  by  185  wood  engravings.  8vo $4.00 

BYRNE. — Pocket-Book  for  Railroad  and  Civil  Engineers: 

Containing  New,  Exact  and  Concise  Methods  for  Laying  out 
Railroad  Curves,  Switches,  Frog  Angles  and  Crossings;  the 
Staking  out  of  work;  Levelling;  the  Calculation  of  Cuttings; 
Embankments;  Earthwork,  etc.  By  OLIVER  BYRNE.  18mo., 
full  bound,  pocketbook  form $1.50 

BYRNE.— The  Practical  Metal- Worker's  Assistant: 

Comprising  Metallurgic  Chemistry;  the  Arts  of  Working  all 
Metals  and  Alloys;  Forging  of  Iron  and  Steel;  Hardening  and 
Tempering;  Melting  and  Mixing;  Casting  and  Founding; 
Works  in  Sheet  Metals;  the  Process  Dependent  on  the  Duc- 
tility of  the  Metals;  Soldering;  etc.  By  JOHN  PERCY.  The 
Manufacture  of  Malleable  Iron  Castings,  and  Improvements 
in  Bessemer  Steel.  By  A.  A.  FESQUET,  Chemist  and  En- 
gineer. With  over  Six  Hundred  Engravings,  Illustrating 
every  Branch  of  the  Subject.  8vo $3.50 

CABINET   MAKER'S    ALBUM    OF    FURNITURE: 

Comprising  a  Collection  of  Designs  for  various  Styles  of 
Furniture.  Illustrated  by  Forty-eight  Large  and  Beauti- 
fully Engraved  Plates.  Oblong,  8vo $1.50 

CALLINGHAM.— Sign  Writing  and  Glass  Embossing: 
A  complete  Practical  Illustrated  Manual  of  the  Art.    By 
JAMES  CALLINGHAM.    To  which  are  added  Numerous  Alpha- 
bets and  the  Art  of  Letter  Painting  Made  Easy.    By  JAMES 
C.   BADENOCH.    258  pages.    12mo $1.50 

CAREY.— A   Memoir   of   Henry   C.    Carey: 
By  DR.  WM.  ELDER.    With  a  portrait.    8vo.,  cloth 75 

CAREY.— The  Works  of  Henry  C.  Carey: 
Manual    of    Social    Science.    Condensed    from    Carey's 
"Principles  of  Social  Science."    By  KATE  McKEAN    1  vol. 
12mo ..$2.00 


8        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

Miscellaneous  Works.    With  a  Portrait.  2  vols.  8vo.  $10.00 

Past,  Present  and  Future.     8vo $2.50 

Principles  of  Social  Science.     3  volumes,  8vo $10.00 

The  Slave-Trade,  Domestic  and  Foreign;    Why  it  Exists, 

and  How  it  may  be  Extinguished  (1853).    8vo $2.00 

The  Unity  of  Law:  As  Exhibited  in  the  Relations  of  Phys- 
ical, Social,  Mental  and  Moral  Science  (1872).  8vo $2.50 

COOLEY.— A  Complete  Practical  Treatise  on  Perfumery:. 

Being  a  Hand-book  of  Perfumes,  Cosmetics  and  other  Toilet 
Articles,  with  a  Comprehensive  Collection  of  Formulae.  By 
ARNOLD  COOLEY.  12mo $1.00 

COURTNEY. — The  Boiler  Maker's  Assistant  in  Drawing, 
Templating,  and  Calculating  Boiler  Work  and  Tank 
Work,  etc. 

Revised  by  D.  K.  CLARK.    102  ills.    Fifth  edition 80 

COURTNEY.— The  Boiler  Maker's  Ready  Reckoner: 

With  Examples  of  Practical  Geometry  and  Templating.  Re- 
vised by  D.  K.  CLARK,  C.  E.  37  illustrations.  Fifth  edi- 
tion  $1.60 

CRISTIANI. — A  Technical  Treatise  on  Soap  and  Candles: 

With  a  Glance  at  the  Industry  of  Fats  and  Oils.  By  R.  S 
Cristiani,  Chemist.  Author  of  "Perfumery  and  Kindred 
Arts."  Illustrated  by  176  Engravings.  581  pages,  8vo 

$15.00 

CROSS. — The  Cotton  Yarn  Spinner: 
Showing  how  the  Preparation  should  be  arranged  for  Differ- 
ent Counts  of  Yarns  by  a  System  more  uniform  than  has  hith- 
erto been  practiced;  by  having  a  Standard  Schedule  from 
which  we  make  all  our  Changes.  By  RICHARD  CROSS.  122 
pp.  12mo * 75 

DAVIDSON.— A  Practical  Manual  of  House  Painting, 
Graining,  Marbling,  and  Sign -Writing: 

Containing  full  information  on  the  processes  of  House  Paint- 
ing in  Oil  and  Distemper,  the  Formation  of  Letters  and 
Practice  of  Sign- Writing,  the  Principles  of  Decorative  Art, 
a  Course  of  Elementary  Drawing  for  House  Painters,  Writers, 
etc.,  and  a  Collection  of  Useful  Receipts.  With  nine  colored 
illustrations  of  Woods  and  Marbles,  and  numerous  wood  en- 
gravings. By  ELLIS  A.  DAVIDSON.  12mo $2.00 

DAVIES. — A  Treatise  on  Earthy  and  Other  Minerals  and 
Mining: 

By  D.  C.  DAVIES.  F.  G.  S.,  Mining  Engineer,  etc.  Illustrated 
by  76  Engravings.  12mo $5.00 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE       9 

DAVIES.— A    Treatise    on    Metalliferous    Minerals    and 
Mining: 

By  D.  C.  DAVIES,  F.  G.  S.,  Mining  Engineer,  Examiner  of 
Mines,  Quarries  and  Collieries.  Illustrated  by  148  engrav- 
ings of  Geological  Formations,  Mining  Operations  and  Ma- 
chinery, drawn  from  the  practice  of  all  parts  of  the  world. 
Fifth  Edition,  thoroughly  Revised  and  much  Enlarged  by 
his  son,  E.  Henry  Davies.  12mo.  524  pages $5.00 

DAVIS. — A    Practical   Treatise   on    the   Manufacture   of 
Brick,  Tiles  and  Terra-Gotta: 

Including  Stiff  Clay,  Dry  Clay,  Hand  Made,  Pressed  or 
Front,  and  Roadway  Paving  Brick,  Enamelled  Brick,  with 
Glazes  and  Colors,  Fire  Brick  and  Blocks,  Silica  Brick,  Carbon 
Brick,  Glass  Pots,  Retorts,  Architectural  Terra-Cotta,  Sewer 
Pipe,  Drain  Tile,  Glazed  and  Unglazed  Roofing  Tile,  Art  Tile, 
Mosaics,  and  Imitation  of  Intrarsia  or  Inlaid  Surfaces.  Com- 
prising every  product  of  Clay  employed  in  Architecture,  En- 
gineering, and  the  Blast  Furnace.  With  a  Detailed  Descrip- 
tion of  the  Different  Clays  employed,  the  Most  Modern  Ma- 
chinery, Tools,  and  Kilns  used,  and  the  Processes  for  Handling 
Disintegrating,  Tempering,  and  Moulding  the  Clay  into  Shape, 
Drying,  Setting,  and  Burning.  By  CHARLES  THOMAS  DAVIS. 
Third  Edition.  Revised  and  in  great  part  rewritten.  Il- 
lustrated by  261  engravings.  662  pages (Scarce.) 

DAVIS. — The  Manufacture  of  Paper: 

Being  a  Description  of  the  various  Processes  for  the  Fabrica- 
tion, Coloring  and  Finishing  of  every  kind  of  Paper,  Includ- 
ing the  Different  Raw  Materials  and  the  Methods  for  De- 
termining their  Values,  the  Tools,  Machines  and  Practical 
Details  connected  with  an  intelligent  and  a  profitable  prose- 
cution of  the  art,  with  special  reference  to  the  best  American 
Practice.  To  which  are  added  a  History  of  Paper,  complete 
Lists  of  Paper-Making  Materials,  List  of  American  Machines, 
Tools  and  Processes  used  in  treating  the  Raw  Materials,  and 
in  Making,  Coloring  and  Finishing  Paper.  By  CHARLES  T. 
DAVIS.  Illustrated  by  156  Engravings.  608  pages.  8vo .  $6.00 

DAWIDOWSKY-BRANNT.— A  Practical  Treatise  on  the 
Raw  Materials  and  Fabrication  of  Glue,  Gelatine, 
Gelatine  Veneers  and  Foils,  Isinglass,  Cements, 
Pastes,  Mucilages,  etc.: 

Based  upon  Actual  Experience.  By  F.  DAWIDOWSKY,  Tech- 
nical Chemist.  Translated  from  the  German,  with  extensive 
additions,  including  a  description  of  the  most  Recent  Ameri- 
can Processes,  by  WILLIAM  T.  BRANNT.  2d  revised  edition, 
350  pages.  (1905)  Price $3.00 


10     HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

DEITE. — A   Practical   Treatise   on   the   Manufacture   of 
Perfumery: 

Comprising  directions  for  making  all  kinds  of  Perfumes, 
Sachet  Powders,  Fumigating  Materials,  Dentrifices,  Cos- 
metics, etc.,  with  a  full  account  of  the  Volatile  Oils,  Balsams, 
Resins,  and  other  Natural  and  Artificial  Perfume-substances, 
including  the  Manufacture  of  Fruit  Ethers,  and  tests  of  their 
purity.  By  DR.  C.  DEITE,  assisted  by  L.  BORCHERT,  F. 
EICHBAUM,  E.  KUGLER,  H.  TOEFFNER,  and  other  experts. 
From  the  German,  by  WM.  T.  BRANNT.  28  Engravings. 
358  pages.  8vo $3.00 

DE  KONINCK-DIETZ.— A  Practical  Manual  of  Chemical 
Analysis  and  Assaying: 

As  applied  to  the  Manufacture  of  Iron  from  its  Ores,  and  to 
Cast  Iron,  Wrought  Iron,  and  Steel,  as  found  in  Commerce. 
By  L.  L.  DEKONINCK,  Dr.  Sc.,  and  E.  DIETZ,  Engineer.  Ed- 
ited with  Notes,  by  ROBERT  MALLET,  F.  R.  S.,  F.  S.  G.,  M. 
I.  C.  E.,  etc.  American  Edition,  Edited  with  Notes  and  an 
Appendix  on  Iron  Ores,  by  A.  A.  FESQUET,  Chemist  and 
Engineer.  12mo $1.00 

DIETERICHS. — A    Treatise    on    Friction,    Lubrication, 
Oils  and  Fats: 

The  Manufacture  of  Lubricating  Oils,  Paint  Oils,  and  of 
Grease,  and  the  Testing  of  Oils.  By  E.  F.  DIETERICHS, 
Member  of  the  Franklin  Institute;  Member  National  Associa- 
tion of  Stationary  Engineers;  Inventor  of  Dietrichs'  Valve- 
Oleum  Lubricating  Oils.  12mo.  (1906.)  A  practical  book 
by  a  practical  man $1.25 

DUNCAN. — Practical  Surveyor's  Guide: 

Containing  the  necessary  information  to  make  any  person  9* 
common  capacity,  a  finished  land  surveyor,  without  the  aid 
of  a  teacher.  By  ANDREW  DUNCAN.  Revised.  72  Engrav- 
ings. 214  pp.  12mo $1.50 

DUPLAIS. — A   Treatise   on    the   Manufacture   and    Dis- 
tillation of  Alcoholic  Liquors: 

Comprising  Accurate  and  Complete  Details  in  Regard  to 
Alcohol  from  Wine,  Molasses,  Beets,  Grain,  Rice,  Potatoes, 
Sorghum,  Asphodel,  Fruits,  etc.;  with  the  Distillation  and 
Rectification  of  Brandy,  Whiskey,  Rum,  Gin,  Swiss  Absinthe, 
etc.,  the  Preparation  of  Aromatic  Waters,  Volatile  Oils  or 
Essences,  Sugars,  Syrups,  Aromatic  Tinctures,  Liqueurs, 
Cordial  Wines,  Effervescing  Wines,  etc.,  the  Ageing  of  Brandy 
and  the  Improvement  of  Spirits,  with  Copious  Directions 
and  Tables  for  Testing  and  Reducing  Spirituous  Liquors,  etc., 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE      11 

etc.    Translated  and  Edited  from  the  French  of  MM.    Du- 
PLAIS.    By  M.   McKENNiE,   M.    D.     Illustrated.    743 
8vo $1 

EDWARDS. — A  Catechism  of  the  Marine  Steam-Engine: 

For  the  use  of  Engineers,  Firemen,  and  Mechanics.  A  Prac- 
tical Work  for  Practical  Men.  By  EMORY  EDWARDS,  Me- 
chanical Engineer.  Illustrated  by  sixty-three  Engravings, 
including  examples  of  the  most  modern  Engines.  Third 
edition,  thoroughly  revised,  with  much  additional  matter. 
12mo.  414  pages $1.50 

EDWARDS.— American     Marine     Engineer,     Theoretical 
and  Practical: 

With  Examples  of  the  latest  and  most  approved  American 
Practice.  By  EMORY  EDWARDS.  85  Illustrations.  12mo.  $1.50 

EDWARDS. — Modern  American  Locomotive  Engines: 

Their  Design,  Construction  and  Management.  By  EMORY 
EDWARDS.  Illustrated.  12mo $1.50 

EDWARDS.— Modern  American  Marine  Engines,  Boilers, 
and  Screw  Propellers: 

Their  Design  and  Construction.     146  pp.    4to $2.00 

EDWARDS.— 900   Examination   Questions   and   Answers: 

For  Engineers  and  Firemen  (Land  and  Marine)  who  desire 
to  obtain  a  United  States  Government  or  State  License. 
Pocket-book  form,  gilt  edge $1.50 

EDWARDS. — The  American  Steam  Engineer: 

Theoretical  and  Practical,  with  examples  of  the  latest  and 
most  approved  American  practice  in  the  design  and  con- 
struction of  Steam  Engines  and  Boilers.  For  the  use  of 
Engineers,  machinists,  boiler-makers,  and  engineering  stu- 
dents. By  EMORY  EDWARDS.  Fully  illustrated.  419  pages. 
12mo $1.50 

EDWARDS.— The  Practical  Steam  Engineer's  Guide: 

In  the  Design,  Construction,  and  Management  of  American 
Stationary,  Portable,  and  Steam  Fire-Engines,  Steam  Pumps, 
Boilers,  Injectors,  Governors,  Indicators,  Pistons  and  Rings, 
Safety  Valves  and  Steam  Gauges.  For  the  use  of  Engineers, 
Firemen,  and  Steam  Users.  By  EMORY  EDWARDS.  Illus- 
trated by  119  engravings.  420  pages.  12mo $2.00 

ELDER. — Conversations    on    the    Principal    Subjects    of 
Political  Economy: 

By  DR.  WILLIAM  ELDER.    8vo .  .$1.50 


12     HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

ELDER.— Questions  of  the  Day: 

Economic  and  Social.    By  DR.  WILLIAM  ELDER.    8vo..$3.00 

ERNI  AND  BROWN.— Mineralogy  Simplified: 

Easy  Methods  of  Identifying  Minerals,  including  Ores,  by 
Means  of  the  Blow-pipe,  by  Flame  Reactions,  by  Humid 
Chemical  Analysis,  and  by  Physical  Tests.  By  HENRI 
ERNI,  A.  M.,  M.  D.  Fourth  Edition,  revised,  re-arranged 
and  with  the  addition  of  entirely  new  matter,  including  Tables 
for  the  Determination  of  Minerals  by  Chemicals  and  Pyrog- 
nostic  Characters,  and  by  Physical  Characters.  By  AMOS 
P.  BROWN,  A.  M.,  Ph.  D.  464  pp.  Illustrated  by  123  En- 
gravings, pocket-book  form,  full  flexible  morocco,  gilt  edges. 

$2.50 

FAIRBAIRN.— The  Principles  of  Mechanism  and  Machi- 
nery of  Transmission : 

Comprising  the  Principles  of  Mechanism,  Wheels,  and  Pul- 
leys, Strength  and  Proportion  of  Shafts,  Coupling-  of  Shafts, 
and  Engaging  and  Disengaging  Gear.  By  SIR  WILLIAM 
FAIRBAIRN,  Bart.,  C  E.  Beautifully  illustrated  by  over  150 
wood-cuts.  In  one  volume.  12mo $2.00 

FLEMING. — Narrow  Gauge  Railways  in  America: 

A  Sketch  of  their  Rise,  Progress,  and  Success.  Valuable 
Statistics  as  to  Grades,  Curves,  Weight  of  Rail,  Locomotives, 
Cars,  etc.  By  HOWARD  FLEMING.  Illustrated.  8vo.  .$1.00 

FLEMMING. — Practical  Tanning: 

A  Handbook  of  Modern  Processes,  Receipts,  and  Sugges- 
tions for  the  Treatment  of  Hides,  Skins,  and  Pelts  of  Every 
Description  By  LEWIS  A.  FLEMMING,  American  Tanner. 
630  pp.  8vo.  1910 $6.00 

FORSYTH. — Book  of  Designs  for  Headstones,  Mural,  and 
other  Monuments : 

Containing  78  Designs.    By  JAMES  FORSYTH.  With  an  In- 
troduction by  CHARLES  BOUTELL,  M.  A.    4to.    Cloth.  .$3.00 
GARDNER. — Everybody's  Paint  Book: 

A  Complete  Guide  to  the  Art  of  Outdoor  and  Indoor  Paint- 
ing 38  Illustrations.  12mo.  183  pp $1.00 

GARDNER. — The  Painter's  Encyclopedia: 

Containing  Definitions  of  all  Important  Words  in  the  Art  of 
Plain  and  Artistic  Painting,  with  Details  of  Practice  in  Coach, 
Carriage,  Railway  Car,  House,  Sign,  and  Ornamental  Paint- 
ing, including  Graining,  Marbling,  Staining,  Varnishing, 
Polishing,  Lettering,  Stenciling,  Gilding,  Bronzing,  etc.  By 
FRANKLIN  B.  GARDNER.  158  illustrations.  12mo.  427  pp 

$2.00 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE      13 

GEE. — The  Goldsmith's  Handbook: 

Containing  full  instructions  for  the  Alloying  and  Working  of 
Gold,  including  the  Art  of  Alloying,  Melting,  Reducing,  Color- 
ing, Collecting,  and  Refining;  the  Processes  of  Manipulation, 
Recovery  of  Waste;  Chemical  and  Physical  Properties  of 
Gold;  with  a  New  System  of  Mixing  its  Alloys;  Solders,  En- 
amels; and  other  Useful  Rules  and  Recipes.  By  GEORGE  E. 
GEE.  12mo $1.25 

GEE. — The  Jeweler's  Assistant  in  the  Art  of  Working  in 
Gold: 

A  Practical  Treatise  for  Masters  and  Workmen.  12mo   $3.00 
GEE. — The  Silversmith's  Handbook: 

Containing  full  instructions  for  the  Alloying  and  Working  of 
Silver,  including  the  different  modes  of  Refining  and  Melting 
the  Metal;  its  Solders;  the  Preparation  of  Imitation  Alloys; 
Methods  of  Manipulation;  Prevention  of  Waste;  Instructions 
for  Improving  and  Finishing  the  Surface  of  the  Work;  together 
with  other  Useful  Information  and  Memoranda.  By  GEORGE 
E.  GEE.  Illustrated.  12mo $1.25 

GOTHIC   ALBUM    FOR   CABINET-MAKERS: 

Designs  for  Gothic  Furniture.  Twenty-three  plates.  Ob- 
long  $1.00 

GRANT.— A   Handbook   on   the  Teeth  of   Gears: 
Their  Curves,  Properties,  and  Practical  Construction.    By 
GEORGE  B.  GRANT     Illustrated.    Third  Edition,  enlarged 
8vo $1.00 

GREGORY. — Mathematics  for  Practical  Men: 
Adapted  to  the  Pursuits  of  Surveyors,  Architects,  Mechan- 
ics,  and  Civil  Engineers.    By  OLINTHUS  GREGORY.    8vo., 
plates $3.00 

GRISWOLD.— Railroad    Engineer's    Pocket    Companion 

for  the  Field: 

Comprising  Rules  for  Calculating  Deflection  Distances  and 
Angles,  Tangential  Distances  and  Angles  and  all  Necessary 
Tables  for  Engineers;  also  the  Art  of  Levelling  from  Prelim- 
inary Survey  to  the  Construction  of  Railroads,  intended 
Expressly  for  the  Young  Engineer,  together  with  Numerous 
Valuable  Rules  and  Examples.  By  W.  GRISWOLD  12mo 
Pocketbook  form $1.50 

GRUNER. — Studies    of    Blast    Furnace    Phenomena: 
By  M.  L.  GRUNER,  President  of  the  General  Council  of  Mines 
of  France,  and  lately  Professor  of  Metallurgy  at  the  Ecole 
des  Mines.    Translated,  with  the  author's  sanction,  with  an 
Appendix,  by  L.  D.  B.  GORDON,  F.  R.  S.  E.,  F.  G.  S.    8vo. 

$2.50 


14      HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

Hand-Book  of  Useful  Tables  for  the  Lumberman,  Farmer 
and  Mechanic: 

Containing  Accurate  Tables  of  Logs  Reduced  to  Inch  Board 
Measure,  Plank,  Scantling  and  Timber  Measure;  Wages  and 
Rent,  by  Week  or  Month;  Capacity  of  Granaries,  Bins  and 
Cisterns;  Land  Measure,  Interest  Tables  with  Directions 
for  finding  the  Interest  on  any  sum  at  4,  5,  6,  7  and  8  per 
cent.,  and  many  other  Useful  Tables.  32mo.,  boards.  186 
pages 25 

HASERICK.— The  Secrets  of   the  Art  of   Dyeing  Wool, 
Cotton  and  Linen: 

Including  Bleaching  and  Coloring  Wool  and  Cotton  Hosiery 
and  Random  Yarns.  A  Treatise  based  on  Economy  and 
Practice  By  E.  C.  HASERICK.  Illustrated  by  323  Dyed 
Patterns  of  the  Yarns  or  Fabrics  8vo $4  50 

HATS  AND  FELTING: 

A  Practical  Treatise  on  their  Manufacture.  By  a  Practical 
Hatter.  Illustrated  by  Drawings  of  Machinery,  etc.  8vo. 

$1.00 
HAUPT. — A  Manual   of  Engineering   Specifications  and 

Contracts : 

By  LEWIS  M.  HAUPT,  C.  E.  Illustrated  with  numerous 
maps.  328  pp.  8vo $2.00 

HAUPT. — Street  Railway  Motors: 

With  Descriptions  and  Cost  of  Plants  and  Operation  of  the 
various  systems  now  in  use.  12mo $1.50 

HAUPT.— The  Topographer,  His  Instruments  and  Meth- 
ods: 

By  LEWIS  M.  HAUPT,  A.  M.,  C.  E.  Illustrated  with  numer- 
ous plates,  maps  and  engravings.  247  pp.  8vo $2.00 

HULME. — Worked     Examination     Questions     in     Plane 
Geometrical   Drawing: 

For  the  Use  of  Candidates  for  the  Royal  Military  Academy, 
Woolwich;  the  Royal  Military  College,  Sandhurst;  the  In- 
dian Civil  Engineering  College,  Cooper's  Hill;  Indian  Public 
Works  and  Telegraph  Department;  Royal  Marine  Light  In- 
fantry; the  Oxford  and  Cambridge  Local  Examinations,  etc. 
By  F.  EDWARD  HULME,  F.  L.  S.,  F.  S.  A.,  Art-Master  Marl- 
borough  College.  Illustrated  by  300  examples.  Small 
quarto $1.00 

KELLEY. — Speeches,  Addresses,  and  Letters  on  Industrial 
and  Financial  Questions: 

By  HON.  WILLIAM  D.  KELLEY,  M.  C.    544  pages.    8vo  $2.00 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE      15 

KEMLO.— Watch  Repairer's  Hand-Book: 

Being  a  Complete  Guide  to  the  Young  Beginner,  in  Taking 
Apart,  Putting  Together,  and  Thoroughly  Cleaning  the 
English  Lever  and  other  Foreign  Watches,  and  all  American 
Watches.  By  F.  KEMLO,  Practical  Watchmaker.  With 
Illustrations.  12mo $1.25 

KICK. — Flour  Manufacturer: 

A  Treatise  on  Milling  Science  and  Practice  By  FREDERICK 
KICK,  Imperial  Regierungsrath,  Professor  of  Mechanical 
Technology  in  the  Imperial  German  Polytechnic  Institute, 
Prague.  Translated  from  the  second  enlarged  and  revised 
edition  with  supplement  by  H.  H.  P.  POWLES,  Assoc.  Memb. 
Institution  of  Civil  Engineers.  Illustrated  with  28  Plates, 
and  167  Wood-cuts.  367  pages.  8vo $7.50 

KINGZETT.— The   History,   Products,   and   Processes   of 
the  Alkali  Trade: 

Including  the  most  Recent  Improvements.  By  CHARLES 
THOMAS  KINGZETT,  Consulting  Chemist.  With  23  illustra- 
tions. 8vo $2.00 

KIRK. — A  Practical  Treatise  on  Foundry  Irons: 

Comprising  Pig  Iron,  and  Fracture  Grading  of  Pig  and  Scrap 
Irons;  Scrap  Irons;  Mixing  Irons;  Elements  and  Metalloids; 
Grading  Iron  by  Analysis;  Chemical  Standards  for  Iron; 
Castings;  Testing  Cast  Iron;  Semi-Steel;  Malleable  Iron; 
Etc.,  Etc.  By  EDWARD  KIRK,  Practical  Moulder  and  Melter, 
Consulting  Expert  in  Melting.  Illustrated.  294  pages. 
8vo.  1911 $3.00 

KIRK.— The  Cupola  Furnace: 

A  Practical  Treatise  on  the  Construction  and  Management  of 
Foundry  Cupolas.  By  EDWARD  KIRK,  Practical  Moulder  and 
Melter,  Consulting  Expert  in  Melting.  Illustrated  by  106 
Engravings.  Third  Edition,  revised  and  enlarged.  482 
pages.  8vo.  1910 $3.50 

KOENIG.— Chemistry  Simplified: 

A  Course  of  Lectures  on  the  Non-Metals,  Based  upon  the 
Natural  Evolution  of  Chemistry.  Designed  Primarily  for 
Engineers.  By  GEORGE  AUGUSTUS  KOENIG,  Ph.  D.,  A.  M , 
E.  M.,  Professor  of  Chemistry,  Michigan  College  of  Mines, 
Houghton.  Illustrated  by  103  Original  Drawings.  449  pp. 
12mo.  (1906) $2.25 

LANGBEIN. — A  Complete  Treatise  on  the  Electro-Deposi- 
tion of  Metals: 

Comprising  Electro-Plating  and  Galvanoplastic  Operations, 
The  Deposition  of  Metals  by  the  Contract  and  Immersion 


16     HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

Processes,  the  Coloring  of  Metals,  the  Methods  of  Grinding 
and  Polishing,  as  well  as  the  Description  of  the  Voltaic  Cells, 
Dynamo-Electric  Machines,  Thermopiles,  and  of  the  Materi- 
als and  Processes  Used  in  Every  Department  of  the  Art. 
Translated  from  the  latest  German  Edition  of  DR.  GEORGE 
LANGBEIN,  Proprietor  of  a  Manufactory  for  Chemical  Pro- 
ducts, Machines,  Apparatus  and  Utensils  for  Electro-Platers, 
and  of  an  Electro-Plating  Establishment  in  Leipzig.  With 
Additions  by  WILLIAM  T.  BRANNT,  Editor  of  "The  Techno- 
Chemical  Receipt  Book."  Seventh  Edition,  Revised  and 
Enlarged.  Illustrated  by  163  Engravings.  8vo.  725  pages. 
1913 $5.00 

LARKIN.— The    Practical     Brass    and     Iron     Founder's 
Guide: 

A  Concise  Treatise  on  Brass  Founding,  Moulding,  the  Metals 
and  their  Alloys,  etc.;  to  which  are  added  Recent  Improve- 
ments in  the  Manufacture  of  Iron,  Steel  by  the  Bessemer 
Process,  etc.,  etc.  By  JAMES  LARKIN,  late  Conductor  of  the 
Brass  Foundry  Department  in  Reany,  Neafie  &  Co.'s  Penn 
Works,  Philadelphia.  New  edition,  revised,  with  extensive 
additions.  414  pages.  12mo $2.50 

LEHNER. — The  Manufacture  of  Ink: 

Comprising  the  Raw  Materials,  and  the  Preparation  of 
Writing,  Copying  and  Hektograph  Inks,  Safety  Inks,  Ink 
Extracts  and  Powders,  etc.  Translated  from  the  German 
of  SIGMUND  LEHNER,  with  additions  by  WILLIAM  T.  BRANNT. 
Illustrated.  12mo $2.00 

LEROUX.— A  Practical  Treatise  on  the  Manufacture  of 
Worsteds  and  Carded  Yarns: 

Comprising  Practical  Mechanics,  with  Rules  and  Calcula- 
tions applied  to  Spinning;  Sorting,  Cleaning,  and  Scouring 
Wools;  the  English  and  French  Methods  of  Combing,  Draw- 
ing, and  Spinning  Worsteds,  and  Manufacturing  Carded 
Yarns.  Translated  from  the  French  of  CHARLES  LEROUX, 
Mechanical  Engineer  and  Superintendent  of  a  Spinning-Mill, 
by  HORATIO  PAINE,  M.  D.,  and  A.  A.  FESQUET,  Chemist  and 
Engineer.  Illustrated  by  twelve  large  Plates.  8vo $3.00 

LESLIE.— Complete  Cookery: 

Directions  for  Cookery  in  its  Various  Branches.  By  Miss 
LESLIE.  Sixtieth  thousand.  Thoroughly  revised,  with  the 
additions  of  New  Receipts.  12mo $1.00 

LE  VAN.— The  Steam  Engine  and  the  Indicator: 

Their  Origin  and  Progressive  Development;  including  the 
Most  Recent  Examples  of  Steam  and  Gas  Motors,  together 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE      17 

with  the  Indicator,  its  Principles,  its  Utility,  and  its  Applica- 
tion. By  WILLIAM  BARNET  LE  VAN.  Illustrated  by  205 
Engravings,  chiefly  of  Indicator-Cards.  469  pp.  8vo.  $2.00 

LIEBER.— Assayer's  Guide: 

Or,  Practical  Directions  to  Assayers,  Miners,  and  Smelters, 
for  the  Tests  and  Assays,  by  Heat  and  by  Wet  Processes,  for 
the  Ores  of  all  the  principal  Metals,  of  Gold  and  Silver  Coins 
and  alloys,  and  of  Coal,  etc.  By  OSCAR  M.  LIEBER.  Re- 
vised. 283  pp.  12mo $1.50 

Lockwood's  Dictionary  of  Terms : 

Used  in  the  Practice  of  Mechanical  Engineering,  embracing 
those  Current  in  the  Drawing  Office,  Pattern  Shop,  Foundry, 
Fitting,  Turning,  Smith's  and  Boiler  Shops,  etc.,  etc.,  com- 
prising upwards  of  Six  Thousand  Definitions.  Edited  by  a 
Foreman  Pattern  Maker,  author  of  "Pattern  Making."  417 
pp.  12mo $3.75 

LUKIN.— The  Lathe  and  Its  Uses: 

Or  Instruction  in  the  Art  of  Turning  Wood  and  Metal.  In- 
cluding a  Description  of  the  Most  Modern  Appliances  for  the 
Ornamentation  of  Plane  and  Curved  Surfaces,  an  Entirely 
Novel  Form  of  Lathe  for  Eccentric  and  Rose-Engine  Turn- 
ing. A  Lathe  and  Planing  Machine  Combined;  and  Other 
Valuable  Matter  Relating  to  the  Art.  Illustrated  by  462 
engravings.  Seventh  Edition.  315  pages  8vo $4.25 

MAUCHLINE.— The  Mine  Foreman's  Hand-Book: 

Of  Practical  and  Theoretical  Inf9rmation  on  the  Opening, 
.Ventilating,  and  Working  of  Collieries.  Questions  and  An- 
swers on  Practical  and  Theoretical  Coal  Mining.  Designed 
to  Assist  Students  and  Others  in  Passing  Examinations  for 
Mine  Foremanships.  By  ROBERT  MAUCHLINE.  3d  Edition. 
Thoroughly  Revised  and  Enlarged  by  F.  ERNEST  BRACKETT. 
134  Engravings.  8vo.  378  pages'.  (1905.) $3.75 

MOLESWORTH.— Pocket-Book  of  Useful  Formula  and 
Memoranda  for  Civil  and  Mechanical  Engineers: 

By  GUILFORD  L.  MOLESWORTH,  Member  of  the  Institution  of 
Civil  Engineers,  Chief  Resident  Engineer  of  the  Ceylon 
Railway.  Full-bound  in  Pocketbook  form $1.00 

MOORE.— The    Universal    Assistant    and    the    Complete 
Mechanic: 

Containing  over  one  million  Industrial  Facts,  Calculations, 
Receipts,  Processes,  Trades  Secrets,  Rules,  Business  Forms, 
Legal  Items,  etc.,  in  every  occupation,  from  the  Household 
to  the  Manufactory.  By  R.  MOORE.  Illustrated  by  500 
Engravings.  12mo $2.50 


18      HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

NAPIER.— A  System  of  Chemistry  Applied  to  Dyeing: 

By  JAMES  NAPIER,  F.  C.  S.  A  New  and  Thoroughly  Revised 
Edition.  Completely  brought  up  to  the  present  state  of  the 
Science,  including  the  Chemistry  of  Coal  Tar  Colors,  by  A. 
A.  FESQUET,  Chemist  and  Engineer.  With  an  Appendix  on 
Dyeing  and  Calico  Printing,  as  shown  at  the  Universal  Ex- 
position, Paris,  1867.  Illustrated.  8vo.  422  pages . . .  $2.00 

NICHOLLS.— The  Theoretical  and  Practical  Boiler-Maker 
and  Engineer's  Reference  Book: 

Containing  a  variety  of  Useful  Information  for  Employers 
of  Labor,  Foremen  and  Working  Boiler-Makers,  Iron,  Copper, 
and  Tinsmiths,  Draughtsmen,  Engineers,  the  General  Steam- 
using  Public,  and  for  the  Use  of  Science  Schools  and  classes 
By  SAMUEL  NICHOLLS.  Illustrated  by  sixteen  plates.  12mo. 

$2.50 

NYSTROM. — On  Technological  Education  and  the  Con- 
struction of  Ships  and  Screw  Propellers 
For  Naval  and  Marine  Engineers.  By  JOHN  W.  NYSTROM, 
late  Acting  Chief  Engineer,  U.  S.  N.  Second  Edition,  Re- 
vised, with  additional  matter.  Illustrated  by  seven  En- 
gravings. 12mo $1.00 

O'NEILL. — A  Dictionary  of  Dyeing  and  Calico  Printing: 

Containing  a  brief  account  9f  all  the  Substances  and  Pro- 
cesses in  use  in  the  Art  of  Dyeing  and  Printing  Textile  Fabrics; 
with  Practical  Receipts  and  Scientific  Information.  By 
CHARLES  O'NEILL,  Analytical  Chemist.  To  which  is  added 
an  Essay  on  Coal  Tar  Colors  and  their  application  to  Dyeing 
and  Calico  Printing.  By  A.  A.  FESQUET,  Chemist  and  En- 
gineer. With  an  appendix  on  Dyeing  and  Calico  Printing, 
as  shown  at  the  Universal  Exposition,  Paris,  1867.  8vo. 
491  pages $2.00 

ORTON.— Underground  Treasures: 

How  and  Where  to  Find  Them.  A  Key  for  the  Ready  De- 
termination of  all  the  Useful  Minerals  within  the  United 
States.  By  JAMES  ORTON,  A.  M.,  Late  Professor  of  Natural 
History  in  Vassar  College,  N.  Y.;  author  of  the  "Andes  and 
the  Amazon,"  etc.  A  New  Edition,  with  An  Appendix  on 
Ore  Deposits  and  Testing  Minerals.  (1901.)  Illustrated. 

$1.50 
OSBORN. — A  Practical  Manual  of  Minerals,  Mines  and 

Mining: 

Comprising  the  Physical  Properties,  Geologic  Position;  Local 
Occurrence  and  Associations  of  the  Useful  Minerals,  their 
Methods  of  Chemical  Analysis  and  Assay;  together  with 
Various  Systems  of  Excavating  and  Timbering,  Brick  and 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE      19 

Masonry  Work,  during  Driving,  Lining,  Bracing  and  other 
Operations,  etc.  By  PROF.  H.  S.  OSBORN,  LL.  D.,  Author  of 
"The  Prospector's  Field-Book  and  Guide."  171  Engravings. 
Second  Edition,  Revised.  8vo $4.50 

OSBORN.— The  Prospector's  Field  Book  and  Guide: 

In  the  Search  For  and  the  Easy  Determination  of  Ores  and 
Other  Useful  Minerals.  By  PROF.  H.  S.  OSBORN,  LL.  D, 
Illustrated  by  66  Engravings.  Eighth  Edition.  Revised 
and  Enlarged.  401  pages.  12mo  (1910.) $1.50 

OVERMAN.— The  Moulder's  and  Founder's  Pocket  Guide: 

A  Treatise  on  Moulding  and  Founding  in  Green-sand,  Dry- 
sand,  Loam,  and  Cement;  the  Moulding  of  Machine  Frames, 
Mill-gear,  Hollow  Ware,  Ornaments,  Trinkets,  Bells,  and 
Statues;  Description  of  Moulds  for  Iron,  Bronze,  Brass,  and 
other  Metals;  Plaster  of  Paris,  Sulphur,  Wax,  etc.;  the  Con- 
struction of  Melting  Furnaces,  the  Melting  and  Founding  of 
Metals;  the  Composition  of  Alloys  and  their  Nature,  etc., 
etc.  By  FREDERICK  OVERMAN,  M.  E.  A  new  Edition,  to 
which  is  added  a  Supplement  on  Statuary  and  Ornamental 
Moulding,  Ordnance,  Malleable  Iron  Castings,  etc.  By  A. 
A.  FESQUET,  Chemist  and  Engineer.  Illustrated  by  44 
engravings.  12mo $2.00 

PAINTER,  GILDER,  AND  VARNISHER'S  COMPANION: 

Comprising  the  Manufacture  and  Test  of  Pigments,  the  Arts 
of  Painting,  Graining,  Marbling,  Staining,  Sign-writing, 
Varnishing,  Glass-staining,  and  Gilding  on  Glass;  together 
with  Coach  Painting  and  Varnishing,  and  the  Principles  of 
the  Harmony  and  Contrast  of  Colors.  Twenty-seventh 
Edition.  Revised,  Enlarged,  and  in  great  part  Rewritten. 
By  WILLIAM  T.  BRANNT,  Editor  of  "Varnishes,  Lacquers, 
Printing  Inks  and  Sealing  Waxes."  Illustrated.  395  pp. 
12mo $1.50 

PERCY.— The  Manufacturing  of  Russian  Sheet-Iron: 
By  JOHN  PERCY,  M.  D.,  F.  R.  S.    Paper 25 

POSSELT. — Cotton  Manufacturing: 
Part  I.    Dealing  with  the  Fibre,  Ginning,  Mixing,  Picking, 
Scutching  and  Carding.    By  E.  A.  POSSELT.     104  Illustra- 
tions, 190  pp $3.00 

Part  II.    Combing,  Drawing,  Roller  Covering  and  Fly  Frame, 

$3.00 

POSSELT. — The   Jacquard   Machine   Analysed   and    Ex- 
plained : 

With  an  Appendix  on  the  Preparation  of  Jacquard  Cards,  and 
Practical  Hints  to  Learners  of  Jacquard  Designing.  By  E. 
A.  POSSELT.  With  230  Illustrations  and  numerous  diagrams. 
127  pp.  4to $3.00 


20     HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

POSSELT.— Recent  Improvements  in  Textile  Machinery 
Relating  to  Weaving: 

Giving  the  Most  Modern  Points  on  the  Construction  of  all 
Kinds  of  Looms,  Warpers,  Beamers,  Slashers,  Winders, 
Spoolers,  Reeds,  Temples,  Shuttles,  Bobbins,  Heddles,  Heddle 
Frames,  Pickers,  Jacquards,  Card  Stampers,  Etc.,  Etc.  By 
E.  A.  POSSELT.  4to.  Part  I,  600  ills.;  Part  II,  600  ills. 
Each  part $3.00 

POSSELT.— Recent  Improvements  in  Textile  Machinery, 
Part  III: 

Processes  Required  for  Converting  Wool,  Cotton,  Silk,  from 
Fibre  to  Finished  Fabric,  Covering  both  Woven  and  Knit 
Goods;  Construction  of  the  most  Modern  Improvements  in 
Preparatory  .Machinery,  Carding,  Combing,  Drawing,  and 
Spinning  Machinery,  Winding,  Warping,  Slashing  Machinery, 
Looms,  Machinery  for  Knit  Goods,  Dye  Stuffs,  Chemicals, 
Soaps,  Latest  Improved  Accessories  Relating  to  Construc- 
tion and  Equipment  of  Modern  Textile  Manufacturing  Plants 
By  E.  A.  POSSELT.  Completely  Illustrated.  4to $7.50 

POSSELT.— Technology  of  Textile  Design: 

The  Most  Complete  Treatise  on  the  Construction  and  Appli- 
cation of  Weaves  for  all  Textile  Fabrics  and  the  Analysis  of 
Cloth.  By  E.  A.  POSSELT.  1,500  Illustrations.  4to.  .$5.00 

POSSELT.— Textile  Calculations: 

A  Guide  to  Calculations  Relating  to  the  Manufacture  of  all 
Kinds  of  Yarns  and  Fabrics,  the  Analysis  of  Cloth,  Speed, 
Power  and  Belt  Calculations.  By  E.  A.  POSSELT.  Illus- 
trated. 4to $2.00 

REGNAULT.— Elements  of  Chemistry: 
By  M.  V.  REGNAULT.  Translated  from  the  French  by  T. 
FORREST  BETTON,  M.  D.,  and  edited,  with  Notes,  by  JAMES 
C.  BOOTH,  Melter  and  Refiner  U.  S.  Mint,  and  WILLIAM  L. 
FABER,  Metallurgist  and  Mining  Engineer.  Illustrated  by 
nearly  700  wood-engravings  Comprising  nearly  1,500  pages. 
In  two  volumes,  8vo.,  cloth $5.00 

RICH. — Artistic  Horse-Shoeing: 

A  Practical  and  Scientific  Treatise,  giving  Improved  Methods 
of  Shoeing,  with  Special  Directions  for  Shaping  Shoes  to  Cure 
Different  Diseases  of  the  Foot,  and  the  Correction  of  Faulty 
Action  in  Trotters.  By  GEORGE  E.  RICH.  362  Illustrations. 
217  pages.  12mo $2.00 

RICHARDSON.— Practical  Blacksmithing : 

A  Collection  of  Articles  Contributed  at  Different  Times  by 
Skilled  Workmen  to  the  columns  of  "The  Blacksmith  and 
Wheelwright,"  and  Covering  nearly  the  Whole  Range  of 
Blacksmithing,  from  the  Simplest  Job  of  Work  to  some  of  the 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE      21 

most  Complex  Forgings.  Compiled  and  Edited  by  M.  T. 
RICHARDSON. 

Vol. I.    210  Illustrations.    224  pages.     12mo $1.00 

Vol.    II.    230  Illustrations.    262  pages.     12mo $1.00 

Vol.    III.    390  Illustrations.    307  pages.     12mo $1.00 

Vol.     IV.    226  Illustrations.    276  pages.     12mo $1.00 

RICHARDSON.— Practical  Carriage  Building: 
Comprising  Numerous  Short  Practical  Articles  upon  Carriage 
and  Wagon  Woodwork;  Plans  for  Factories;  Shop  and  Bench 
Tools;  Convenient  Appliances  for  Repair  Work;  Methods  of 
Working;  Peculiarities  of  Bent  Timber;  Construction  of 
Carriage  Parts;  Repairing  Wheels;  Forms  of  Tenons  and  Mor- 
tises; Together  with  a  Variety  of  Useful  Hints  and  Sugges- 
tions to  Woodworkers.  Compiled  by  M.  T.  RICHARDSON. 

Vol.  I.  228  Illustrations.  222  pages $1.00 

Vol.    II.    283  Illustrations.    280  pages $100 

RICHARDSON.— The  Practical  Horseshoer: 
Being  a  Collection  of  Articles  on  Horseshoeing  in  all  its 
Branches  which  have  appeared  from  time  to  time  in  the  col- 
umns of  "The  Blacksmith  and  Wheelwright,"  etc.    Compiled 
and  edited  by  M.  T.  RICHARDSON.     174  Illustrations,  $1.00 

RIFFAULT,  VERGNAUD,  and  TOUSSAINT.— A  Practical 
Treatise  on  the  Manufacture  of  Colors  for  Painting: 
Comprising  the  Origin,  Definition,  and  Classification  of  Colors, 
the  Treatment  of  the  Raw  Materials;  the  best  Formulae  and 
the  Newest  Processes  for  the  Preparation  of  every  description 
of  Pigment,  and  the  Necessary  Apparatus  and  Directions  for 
its  use;  Dryers;  the  Testing,  Application,  and  Qualities  of 
Paints,  etc.,  etc.  By  MM.  RIFFAULT,  VERGNAUD,  and 
TOUSSAINT,  Revised  and  Edited  by  M.  F.  MALPEYRE,  Trans- 
lated from  the  French  by  A.  A.  FESQUET.  Illustrated  by 
Eighty  Engravings.  659  pp.  8vo $5.00 

ROPER. — Catechism    for    Steam    Engineers    and    Elec- 
tricians : 

Including  the  Construction  and  Management  of  Steam  En- 
gines, Steam  Boilers  and  Electric  Plants.  By  STEPHEN 
ROPER.  Twenty-first  edition,  rewritten  and  greatly  enlarged 
by  E.  R.  KELLER  and  C.  W.  PIKE.  365  pages.  Illustrations. 

18mo.f  tucks,  gilt $2.00 

OPER.— Engineer's  Handy  Book: 

Containing  Facts,  Formulae,  Tables  and  Questions  on  Power, 
its  Generation,  Transmission  and  Measurement;  Heat,  Fuel, 
and  Steam;  The  Steam  Boiler  and  Accessories;  Steam  Engines 
and  their  Parts;  Steam  Engine  Indicator;  Gas  and  Gasoline 
Engines;  Materials;  their  Properties  and  Strength;  Together 
with  a  Discussion  of  the  Fundamental  Experiments  in  Elec- 
tricity, and  an  Explanation  of  Dynamos,  Motors,  Batteries, 
etc.,  and  Rules  for  Calculating  Sizes  of  Wires.  By  STEPHEN 


22     HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

ROPER.  15th  edition.  Revised  and  Enlarged  by  E.  R. 
KELLER,  M.  E.,  and  C.  W.  PIKE,  B.  S.  With  numerous 
Illustrations.  Pocket-book  form.  Leather $3.50 

ROPER. — Hand-Book  of  Land  and  Marine  Engines: 

.  Including  the  Modeling,  Construction,  Running,  and  Man- 
agement of  Land  and  Marine  Engines  and  Boilers.  With 
Illustrations.  By  STEPHEN  ROPER,  Engineer.  Sixth  Edition. 
12mo.,  tucks,  gilt  edge. $3.50 

ROPER. — Hand-Book  of  the  Locomotive: 

Including  the  Construction  of  Engines  and  Boilers,  and  the 
Construction,  Management,  and  Running  of  Locomotives. 
By  STEPHEN  ROPER.  Eleventh  Edition.  18mo.,  tucks,  gilt 
edge $2.50 

ROPER. — Hand-Book  of  Modern  Steam  Fire-Engines; 
With  Illustrations.  By  STEPHEN  ROPER,  Engineer.  Fourth 
Edition,  12mo.,  tucks,  gilt  edge. $3.50 

ROPER. — Instructions  and  Suggestions  for  Engineers  and 
Firemen: 

By  STEPHEN  ROPER,  Engineer.     18mo.,  Morocco $2.00 

OPER. — Questions    and    Answers    for    Stationary    and 

Marine  Engineers  and  Electricians: 
With  a  Chapter  of  What  to  Do  in  Case  of  Accidents.  By 
STEPHEN  ROPER,  Engineer.  Sixth  Edition,  Rewritten  and 
Greatly  Enlarged  by  EDWIN  R.  KELLER,  M.  E.,  and  CLAYTON 
W.  PIKE,  B.  A.  306  pp.  Morocco,  pocketbook  form,  gilt 
edges $2.00 

ROPER. — The  Steam  Boiler:  Its  Care  and  Management: 
By  STEPHEN  ROPER,  Engineer.  1 3mo.,  tuck,  gilt  edges.  $2.00 

ROPER. — Use  and  Abuse  of  the  Steam  Boiler: 
By  STEPHEN  ROPER,  Engineer.    Ninth  Edition,  with  Illus- 
trations.    18mo.,  tucks,  gilt  edge $2.00 

ROPER. — The  Young  Engineer's  Own  Book: 
Containing  an  Explanation  of  the  Principle  and  Theories  on 
which  the  Steam  Engine  as  a  Prime  Mover  is  based.    By 
STEPHEN   ROPER,   Engineer.    160   Illustrations,   363   pages. 
18mo.,  tuck $2.50 

ROSE. — The  Complete  Practical  Machinist: 
Embracing  Lathe  Work,  Vise  Work,  Drills  and  Drilling,  Taps 
and  Dies,  Hardening  and  Tempering,  the  Making  and  Use  of 
Tools,  Tool  Grinding,  Marking  out  work,  Machine  Tools,  etc. 
By  JOSHUA  ROSE.  395  Engravings.  Nineteenth  Edition, 
greatly  Enlarged  with  New  and  Valuable  Matter.  12mo., 
504  pages $2.50 

ROSE.— Mechanical  Drawing  Self -Taught: 
Comprising  Instructions  in  the  Selection  and  Preparation  of 
Drawing  Instruments,  Elementary  Instruction  in  practical 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE      23 

Mechanical  Drawing,  together  with  Examples  in  Simple 
Geometry  and  Elementary  Mechanism,  including  Screw 
Threads,  Gear  Wheels,  Mechanical  Motions,  Engines  and 
Boilers.  By  JOSHUA  ROSE,  M.  E.  Illustrated  by  330  En- 
gravings. 8vo.  313  pages $3.50 

ROSE.— The  Slide- Valve  Practically  Explained: 

Embracing  simple  and  complete  Practical  Demonstrations  of 
the  operation  of  each  element  in  a  Slide-valve  Movement, 
and  illustrating  the  effects  of  Variations  in  their  Proportions 
by  examples  carefully  selected  from  the  most  recent  and 
successful  practice.  By  JOSHUA  ROSE,  M.  E.  Illustrated 
by  35  Engravings $1.00 

ROSE. — Steam  Boilers: 

A  Practical  Treatise  on  Boiler  Construction  and  Examination, 
for  the  Use  of  Practical  Boiler  Makers,  Boiler  Users,  and  In- 
spectors; and  embracing  in  plain  figures  all  the  calculations 
necessary  in  Designing  or  Classifying  Steam  Boilers.  By 
JOSHUA  ROSE,  M.  E.  Illustrated  by  73  Engravings.  250 
pages.  8vo $2.00 

ROSS.— The    Blowpipe    in    Chemistry,    Mineralogy    and 
Geology: 

Containing  all  Known  Methods  of  Anhydrous  Analysis,  many 
Working  Examples,  and  Instructions  for  Making  Apparatus. 
By  LIEUT.  COLONEL  W  A.  Ross,  R.  A.,  F.  G.  S.  With  120 
Illustrations.  12mo $2.00 

SCHRIBER. — The  Complete  Carriage  and  Wagon  Painter: 

A  Concise  Compendium  of  the  Art  of  Painting  Carriages, 
Wagons,  and  Sleighs,  embracing  Full  Directions  in  all  the 
Various  Branches,  including  Lettering,  Scrolling,  Ornament- 
ing, Striping,  Varnishing,  and  Coloring,  with  numerous  Re- 
cipes for  Mixing  Colors.  73  Illustrations.  177  pp.  12mo. 

$1.00 

SHAW. — Civil  Architecture: 

Being  a  Complete  Theoretical  and  Practical  System  of  Build- 
ing, containing  the  Fundamental  Principles  of  the  Art.  By 
EDWARD  SHAW,  Architect.  To  which  is  added  a  Treatise  on 
Gothic  Architecture,  etc.  By  THOMAS  W.  SILLOWAY  and 
GEORGE  M.  HARDING,  Architects.  The  whole  illustrated  by 
102  quarto  plates  finely  engraved  on  copper.  Eleventh  Edi- 
tion 4to $5.00 

SHERRATT. — The  Elements  of  Hand-Railing: 

Simplified  and  Explained  in  Concise  Problems  that  are  Easily 
Understood.  The  whole  illustrated  with  Thirty-eight  Ac- 
curate and  Original  Plates,  Founded  on  Geometrical  Principles, 
and  showing 'how  to  Make  Rail  Without  Centre  Joints,  Mak- 
ing Better  Rail  of  the  Same  Material,  with  Half  the  Labor, 


24     HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

and  Showing  How  to  Lay  Out  Stairs  of  all  Kinds.  By  R.  J. 
SHERRATT.  Folio $2.50 

SHUNK. — A  Practical  Treatise  on  Railway  Curves  and 
Location  for  Young  Engineers: 

By  W  F.  SHUNK,  C.  E.  12mo.  Full  bound  pocket-book 
form $2.00 

SLOANE. — Home  Experiments  in  Science: 
By  T.  O'CON9R  SLOANE,  E.  M.,  A.  M.,  Ph.  D.    Illustrated 
by  91  Engravings.     12mo $1.00 

SLOAN. — Homestead  Architecture: 
Containing  Forty  Designs  for  Villas,  Cottages,  and  Farm- 
houses, with  Essays  on  Style,  Construction,  Landscape  Gar- 
dening, Furniture,  etc.,  etc.     Illustrated  by  upwards  of  200 
Engravings.    By  SAMUEL  SLOAN,  Architect.    8vo $2.00 

SMITH.— The  Dyer's  Instructor: 

Comprising  Practical  Instructions  in  the  Art  of  Dyeing  Silk, 
Cotton,  Wool,  and  Worsted,  and  Woolen  Goods;  containing 
nearly  800  Receipts.  To  which  is  added  a  Treatise  on  the 
Art  of  Padding;  and  the  Printing  of  Silk  Warps,  Skeins,  and 
Handkerchiefs,  and  the  various  Mordants  and  Colors  for  the 
different  styles  of  such  -work.  By  DAVID  SMITH,  Pattern 
Dyer.  12mo $1.00 

SMITH.— A  Manual  of  Political  Economy: 
By  E.  PESHINE  SMITH.    A  New  Edition,  to  which  is  added 
a  full  Index.     12mo $1.25 

SMITH. — Parks  and  Pleasure- Grounds: 
Or  Practical  Notes  on  Country  Residences,  Villas,  Public 
Parks,  and  Gardens.    By  CHARLES  H.  J.  SMITH,  Landscape 
Gardener  and  Garden  Architect,  etc.,  etc.     12mo $2.00 

SNIVELY. — The    Elements    of    Systematic     Qualitative 

Chemical  Analysis: 

A  Hand-book  for  Beginners.  By  JOHN  H.  SNIVELY,  Phr.  D. 
16mo $2.00 

STOKES. — The  Cabinet  Maker  and  Upholsterer's  Com- 
panion : 

Comprising  the  Art  of  Drawing,  as  applicable  to  Cabinet 
Work;  Veneering,  Inlaying,  and  Buhl- Work;  the  Art  of  Dye- 
ing and  Staining  Wood,  Ivory,  Bone,  Tortoise-Shell,  etc. 
Directions  for  Lacquering,  Japanning,  and  Varnishing;  to 
make  French  Polish,  Glues,  Cements,  and  Compositions; 
with  numerous  Receipts,  useful  to  workmen  generally.  By 
J.  STOKES.  Illustrated.  A  New  Edition,  with  an  Appendix 
upon  French  Polishing,  Staining,  Imitating,  Varnishing,  etc., 
etc.  12mo $1.25 

STRENGTH  AND  OTHER      ROPERTIES   OF    METALS: 
Reports  of  Experiments  on  the  Strength  and  other  Properties 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE      25 

of  Metals  for  Cannon  With  a  Description  of  the  Machines 
for  Testing  Metals,  and  of  the  Classification  of  Cannon  in 
service.  By  Officers  of  the  Ordnance  Department,  U.  S. 
Army.  By  authority  of  the  Secretary  of  War.  Illustrated 
by  25  large  steel  plates.  Quarto $3.00 

SULZ. — A  Treatise  on  Beverages: 

Or  the  Complete  Practical  Bottler.  Full  Instructions  for 
Laboratory  Work  with  Original  Practical  Recipes  for  all 
kinds  of  Carbonated  Drinks,  Mineral  Waters,  Flavoring 
Extracts,  Syrups,  etc.  By  CHARLES  HERMAN  SULZ,  Tech- 
nical Chemist  and  Practical  Bottler.  Illustrated  by  428 

Engravings.    818  pp.    8vo $7.50 

SYME. — Outlines  of  an  Industrial  Science: 
By  DAVID  SYME.    12mo $2.00 

TABLES  SHOWING  THE  WEIGHT  OF  ROUND,  SQUARE 
AND  FLAT  BAR  IRON,  STEEL,  ETC. 

By  Measurement.    Cloth 63 

TEMPLETON. — The  Practical  Examinator  on  Steam  and 
the  Steam-Engine: 

With  Instructive  References  relative  thereto,  arranged  for 
the  Use  of  Engineers,  Students,  and  others.  By  WILLIAM 

TEMPLETON,  Engineer     12mo $1.00 

THALLNER.— Tool-Steel : 

A  Concise  Hand-book  on  Tool-Steel  in  General.  Its  Treat- 
ment in  the  Operations  of  Forging,  Annealing,  Hardening, 
Tempering,  etc.,  and  the  Appliances  Therefor.  By  OTTO 
THALLNER,  Manager  in  Chief  of  the  Tool-Steel  Works,  Bis- 
marckhutte,  Germany.  From  the  German  by  WILLIAM  T. 
BRANNT.  Illustrated  by  69  Engravings.  194  pages  8vo. 
1902 $2.00 

THAUSING.— The  Theory  and  Practice  of  the  Preparation 
of  Malt  and  the  Fabrication  of  Beer: 

With  especial  reference  to  the  Vienna  Process  of  Brewing. 
Elaborated  from  personal  experience  by  JULIUS  E.  THAUSING, 
Professor  at  the  School  for  Brewers,  and  at  the  Agricultural 
Institute,  Modling,  near  Vienna.  Translated  from  the  Ger- 
man by  WILLIAM  T.  BRANNT.  Thoroughly  and  elaborately 
edited,  with  much  American  matter,  and  according  to  the 
latest  and  most  Scientific  Practice,  by  A.  SCHWARZ  and  DR. 
A  H.  BAUER.  Illustrated  by  140  Engravings.  8vo.  815 

pages $10.00 

TOMPKINS.— Cotton  and  Cotton  Oil: 
Cotton:    Planting,  Cultivating,  Harvesting  and  Preparation 
fpr  Market.    Cotton  Seed  Oil  Mills:    Organization,  Construc- 
tion and  Operation.    Cattle  Feeding:    Production  of  Beef 
and  Dairy  Products,  Cotton  Seed  Meal  and  Hulls  as  Stock 


26     HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

Feed.  Fertilizers:  Manufacture,  Manipulation  and  Uses. 
By  D.  A.  TOMPKINS.  8vo.  494pp.  Illustrated $7.50 

TOMPKINS.— Cotton  Mill,  Commercial  Features: 

A  Text-Book  for  the  Use  of  Textile  Schools  and  Investors. 
With  Tables  showing  Cost  of  Machinery  and  Equipments 
for  Mills  making  Cotton  Yarns  and  Plain  Cotton  Cloths.  By 
D.  A.  TOMPKINS.  8vo.  240  pp.  Illustrated $5.00 

TOMPKINS.— Cotton  Mill  Processes  and  Calculations: 

An  Elementary  Text-Book  for  the  Use  of  Textile  Schools  and 
for  Home  Study.  By  D.  A.  TOMPKINS.  312  pp.  8vo. 
Illustrated $5.00 

TURNER'S  (THE)  COMPANION: 

Containing  Instructions  in  Concentric,  Elliptic,  and  Eccen- 
tric Turning;  also  various  Plates  of  Chucks,  Tools,  and  In- 
struments; and  Directions  for  using  the  Eccentric  Cutter, 
Drill,  Vertical  Cutter,  and  Circular  Rest;  with  Patterns  and 
Instructions  for  working  them.  12mo $1.00 

VAN  CLEVE.— The  English  and  American  Mechanic: 
Comprising  a  Collection  of  Over  Three  Thousand  Receipts, 
Rules,  and  Tables,  designed  for  the  Use  of  every  Mechanic 
and  Manufacturer.    By  B.  FRANK  VAN  CLEVE.    Illustrated. 
500  pp.     12mo $2.00 

VAN  DER  BURG.— School  of  Painting  for  the  Imitation 

of  Woods  and  Marbles : 

A  Complete,  Practical  Treatise  on  the  Art  and  Craft  of  Grain- 
ing and  Marbling  with  the  Tools  and  Appliances.  36  Plates. 
Folio,  12x20  inches $6.00 

VILLE.— The  School  of  Chemical  Manures: 
Or,  Elementary  Principles  in  the  Use  of  Fertilizing  Agents 
From  the  French  of  M.  GEO.  VILLE,  by  A.  A.  FESQUET, 
Chemist  and  Engineer.    With  Illustrations.     12mo $1.25 

VOGDES.— The   Architect's   and   Builder's   Pocket-Com- 
panion and  Price- Book: 

Consisting  of  a  Short  but  Comprehensive  Epitome  of  Deci- 
mals, Duodecimals,  Geometry  and  Mensuration;  with  Tables 
of  United  States  Measures,  Sizes,  Weights,  Strength,  etc.,  of 
Iron,  Wood,  Stone,  Brick,  Cement  and  Concretes,  Quanti- 
ties of  Materials  in  given  Sizes  and  Dimensions  of  Wood, 
Brick  and  Stone;  and  full  and  complete  Bills  of  Prices  for 
Carpenter's  Work  and  Painting;  also,  Rules  for  Computing 
and  Valuing  Brick  and  Brick  Work,  Stone  Work,  Painting, 
Plastering,  with  a  Vocabulary  of  Technical  Terms,  etc.  By 
FRANK  W.  VOGDES,  Architect,  Indianapolis,  Ind.  Enlarged, 
Revised  and  Corrected.  In  one  volume  368  pages,  full- 
bound,  pocketbook  form,  gilt  edges $2.00 

Cloth..  $1.50 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE      27 

WAHNSCHAFFE.— A  Guide  to   the  Scientific  Examina- 
tion of  Soils: 

Comprising  Select  Methods  of  Mechanical  and  Chemical 
Analysis  and  Physical  Investigation.  Translated  from  the 
German  of  DR  F.  WAHNSCHAFFE.  With  additions  by  WIL- 
LIAM T.  BRANNT.  Illustrated  by  25  Engravings.  12mo. 
177  pages $1.50 

WARE.— The  Sugar  Beet: 

Including  a  History  of  the  Beet  Sugar  Industry  in  Europe, 
Varieties  of  the  Sugar  Beet,  Examination,  Soils,  Tillage 
Seeds  and  Sowing,  Yield  and  Cost  of  Cultivation,  Harvest- 
ing, Transportation,  Conservation,  Feeding  Qualities  of  the 
Beet  and  of  the  Pulp,  etc.  By  LEWIS  S.  WARE,  C.  E., 
M.  E.  Illustrated  by  ninety  Engravings.  8vo . . : $2.00 

WARN. — The  Sheet-Metal  Worker's  Instructor: 
For  Zinc,  Sheet-Iron,  Copper,  and  Tin-Plate  Workers,  etc. 
Containing  a  selection  of  Geometrical  Problems;  alsa  Prac- 
tical and  Simple  Rules  for  Describing  the  various  Patterns 
required  in  the  different  branches  of  the  above  Trades.  By 
REUBEN  H.  WARN,  Practical  Tin-Plate  Worker.  To  which  is 
added  an  Appendix,  containing  Instructions  for  Boiler-Mak- 
ing, Mensuration  of  Surfaces  and  Solids,  Rules  for  Calculat- 
ing the  Weights  of  different  Figures  of  Iron  and  Steel,  Tables 
of  the  Weights  of  Iron,  Steel,  etc.  Illustrated  by  thirty- 
two  Plates  and  thirty-seven  Wood  Engravings.  8vo. . .  $2.00 

WARNER. — New  Theorems,   Tables,   and  Diagrams,   for 

the  Computation  of  Earth- work: 

Designed  for  the  use  of  Engineers  in  Preliminary  and  Final 
Estimates,  of  Students  in  Engineering  and  of  Contractors 
and  other  non-professional  Computers.  In  two  parts,  with 
an  Appendix.  Part  I.  A  Practical  Treatise;  Part  II.  A 
Theoretical  Treatise,  and  the  Appendix  Containing  Notes  to 
the  Rules  and  Examples  of  Part  I.;  Explanations  of  the  Con- 
struction of  Scales,  Tables,  and  Diagrams,  and  a  Treatise 
upon  Equivalent  Square  Bases  and  Equivalent  Level  Heights. 
By  JOHN  WARNER,  A.  M.,  Mining  and  Mechanical  Engineer. 
Illustrated  by  14  Plates.  8vo $3.00 

WATSON.— A  Manual  of  the  Hand-Lathe: 
Comprising  Concise  Directions  for  Working  Metals  of  all 
kinds,  Ivory,  Bone  and  Precious  Woods;  Dyeing,  Coloring, 
and  French  Polishing;  Inlaying  by  Veneers,  and  various 
methods  practised  to  produce  Elaborate  work  with  dispatch, 
and  at  Small  Expense.  By  EGBERT  P.  WATSON,  Author  of 
"The  Modern  Practice  of  American  Machinists  and  En- 
gineers. "  Illustrated  by  78  Engravings $1.00 

WATSON.— The  Modern  Practice  of  American  Machinists 

and  Engineers: 
Including  the  Construction,  Application,  and  Use  of  Drills 


28     HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE 

Lathe  Tools,  Cutters  for  Boring  Cylinders,  and  Hollow-work 
generally,  with  the  most  economical  Speed  for  the  same;  the 
Results  verified  by  Actual .  Practice  at  the  Lathe,  the  Vise, 
and  on  the  floor.  Together  with  Workshop  Management, 
Economy  of  Manufacture,  the  Steam  Engine,  Boilers,  Gears, 
Belting,  etc.,  etc.  By  EGBERT  P.  WATSON  Illustrated  by 
eighty-six  Engravings.  12mo $2.00 

WEATHERLY.— Treatise  on  the  Art  of  Boiling  Sugar, 
Crystallizing,  Lozenge-making,  Comfits,  Gum  Goods : 
And  other  processes  for  Confectionery,  including  Methods 
for  Manufacturing  every  Description  of  Raw  and  Refined 
Sugar  Goods.  A  New  and  Enlarged  Edition,  with  an  Appen- 
dix on  Cocoa,  Chocolate,  Chocolate  Confections,  etc.  196 
pages.  12mo.  (1903.) $1.50 

WILL.— Tables  of  Qualitative  Chemical  Analysis: 
With  an  Introductory  Chapter  on  the  Course  of  Analysis 
By  PROFESSOR  HEINRICH  WILL,  of  Giessen,  Germany.  Third 
American,  from  the  eleventh  German  Edition.  Edited  by 
CHARLES  F.  HIMES,  Ph.  D.,  Professor  of  Natural  Science, 
Dickinson  College,  Carlisle,  Pa.  8vo $1.00 

WILLIAMS.— On  Heat  and  Steam: 
Embracing  New  Views  of  Vaporization,  Condensation  and 
Explosion.    By  CHARLES  WYE  WILLIAMS,  A.  I.  C.  E.    Illus- 
trated.   8vo $2.00 

WILSON.— The  Practical  Tool-Maker  and  Designer: 
A  Treatise  upon  the  Designing  of  Tools  and  Fixtures  for 
Machine  Tools  and  Metal  Working  Machinery,  Comprising 
Modern  Examples  of  Machines  with  Fundamental  Designs 
for  Tools  for  the  Actual  Production  of  the  work;  Together 
with  Special  Reference  to  a  Set  of  Tools  for  Machining  the 
Various  Parts  of  a  Bicycle.  Illustrated  by  189  Engravings 
(1898) $2.50 

CONTENTS  :  Introductory.  Chapter  I.  Modern  Tool  Room  and 
Equipment.  II.  Files,  Their  Use  and  Abuse.  III.  Steel  and  Tem- 
pering. IV.  Making  Jigs.  V.  Milling  Machine  Fixtures.  VI.  Tools 
and  Fixtures  for  Screw  Machines.  VII.  Broaching.  VIII.  Punches 
and  Dies  for  Cutting  and  Drop  Press.  IX.  Tools  for  Hollow-ware. 

X.  Embossing :   Metal,   Coin  and  Stamped  Sheet-Metal  Ornaments. 

XI.  Drop  Forging.     XII.  Solid  Drawn  Shells  or  Ferrules  ;  Cupping 
or  Cutting  and  Drawing ;  Breaking  Down  Shells.     XIII.  Annealing, 
Pickling  and  Cleaning.     XIV.  Tools  for  Draw  Bench.     XV.  Cutting 
and  Assembling  Pieces  by  Means  of   Ratchet  Dial   Plates   at  One 
Operation.     XVI.  The  Header.     XVII.  Tools  for  Fox  Lathe.   XVIII. 
Suggestions  for  a  set  of  Tools  for  Machining  the  Various  Parts  of 
a  Bicycle.     XIX.  The  Plater's  Dynamo.     XX.  Conclusion — With  a 
few  Random  Ideas.     Appendix.     Index. 

WORSSAM.— On  Mechanical  Saws: 

From  the  Transaction  of  the  Society  of  Engineers,  1869.  By 
S.  W.  WORSSAM,  JR.  Illustrated  by  Eighteen  large  Plates. 
8vo ..$1.50 


BRANNTS  "SOAP  MAKERS  HAND  BOOK." 


The  most  helpful  and  up-to-date  book  on  the  Art  of  Soap 
Making  in  the  English  language. 

In  one  volume,  8vo,  535  pages,  illustrated  by  54  engravings. 
Price  $6.00  net,  Free  of  Postage  to  any  Address  in  the  World, 
or  by  Express  C.  O.  J>.  freight  paid  to  any  Address  in  the 
United  States  or  Canada. 


PUBLISHED   APRIL,  1912. 


THE 

SOAP  MAKER'S  HAM)  BOOK 


OF 

MATERIALS,  PROCESSES  AND  RECEIPTS  FOR 
EVERY  DESCRIPTION  OF  SOAP 

INCLUDING 

FATS,  FAT  OILS,  AND  FATTY  ACIDS ;   EXAMINATION  OF  FATS  AND  OILS  J 

ALKALIES  ;  TESTING  SODA  AND  POTASH  ;   MACHINES  AND  UTENSILS  J 

HARD  SOAPS  ;  SOFT  SOAPS  ;  TEXTILE  SOAPS  J  WASHING  POWDERS 

AND  ALLIED  PRODUCTS  ;   TOILET  SOAPS,  MEDICATED  SOAPS, 

AND  SOAP  SPECIALTIES  ;   ESSENTIAL  OILS  AND  OTHER 

PERFUMING  MATERIALS  ;   TESTING  SOAPS. 

EDITED   CHIEFLY   FROM   THE   GERMAN   OF 

DR.  C.  DEITE,  A.  ENGELHARDT,  F.  WILTNER, 

AND  NUMEROUS  OTHER  EXPERTS. 

WITH  ADDITIONS 
BY 

WILLIAM  T.  BRANNT, 

EDITOR  OF  "THE  TECHNO  CHEMICAL  RECEIPT  BOOK." 

ILLUSTRATED  BY  FIFTY-FOUR  ENGRAVINGS. 
SECOND  EDITION.  REVISED  AND  IN  GREAT  PART  RE-WRITTEN. 

PHILADELPHIA  : 
HENRY  CAREY  BAIRD  &  CO., 

INDUSTRIAL  PUBLISHERS,  BOOKSELLERS,  AND  IMPORTERS, 

810  WALNUT  STREET. 

1912 


KIRK'S   CUPOLA   FURNACE. 

An  Eminently,  Practical)  TTp-to-Date  Book,  by  an  Expert* 
Third  Thoroughly  Revised  and  Partly  Re-written  Edition* 
In  one  volume,  8vo.,  482  pages,  illustrated  by  one  hundred 
and  six  engravings.  Price  $3.50.  Free  of  Postage  to  any 
Address  in  the  World,  or  by  Express  C.  O.  D.,  freight  paid  to 
any  Address  in  the  United  States  or  Canada. 


PUBLISHED  AUGUST,  1910. 


THE    CUPOLA    FURNACE 

A  PRACTICAL  TREATISE  ON  THE 

CONSTRUCTION  AND  MANAGEMENT 


OF 

FOUNDRY  CUPOLAS: 

COMPRISING 

IMPROVEMENTS  IN  CUPOLAS  AND   METHODS  OF  THEIR  CONSTRUCTION  AND  MANAGE- 
MENT; TUYERES;  MODERN  CUPOLAS;  CUPOLA  FUELS;  FLUXING  OF  IRON;  GETTING 
UP  CUPOLA  STOCK;  RUNNING  A  CONTINUOUS  STREAM;  SCIENTIFICALLY 

DESIGNED  CUPOLAS;  SPARK-CATCHING  DEVICES;    BLAST-PIPES  AND 

BLAST;  BLOWERS;  FOUNDRY  TRAM  RAIL,  ETC.,  ETC. 


BY 

EDWARD   KIRK, 

PRACTICAL  MOULDER  AND  MELTER,  CONSULTING   EXPERT  IN  MELTING. 

Author  of  "  The  Founding  of  Metals?  and  of  Numerous  Papers  on  Cupola  Practice. 

ILLUSTRATED  BY  ONE  HUNDRED  AND  SIX  ENGRAVINGS. 

THIRD  THOROUGHLY  REVISED  AND  PARTLY  RE-WR.TTEN   EDITION. 


PHILADELPHIA  : 
HENRY  CAREY  BAIRD  &  CO., 

INDUSTRIAL  PUBLISHERS,  BOOKSELLERS  AND  IMPORTERS, 
810  WALNUT  STREET. 


14  DAY  USE 

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